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1032c0ba 1# x86 configuration
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2mainmenu "Linux Kernel Configuration for x86"
3
4# Select 32 or 64 bit
5config 64BIT
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6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
8f9ca475 8 ---help---
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9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
11
12config X86_32
13 def_bool !64BIT
14
15config X86_64
16 def_bool 64BIT
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17
18### Arch settings
8d5fffb9 19config X86
3c2362e6 20 def_bool y
e17c6d56 21 select HAVE_AOUT if X86_32
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22 select HAVE_READQ
23 select HAVE_WRITEQ
a5574cf6 24 select HAVE_UNSTABLE_SCHED_CLOCK
ec7748b5 25 select HAVE_IDE
42d4b839 26 select HAVE_OPROFILE
04da8a43 27 select HAVE_PERF_COUNTERS if (!M386 && !M486)
28b2ee20 28 select HAVE_IOREMAP_PROT
3f550096 29 select HAVE_KPROBES
1f972768 30 select ARCH_WANT_OPTIONAL_GPIOLIB
da4276b8 31 select ARCH_WANT_FRAME_POINTERS
7c095e46 32 select HAVE_DMA_ATTRS
9edddaa2 33 select HAVE_KRETPROBES
e4b2b886 34 select HAVE_FTRACE_MCOUNT_RECORD
677aa9f7 35 select HAVE_DYNAMIC_FTRACE
606576ce 36 select HAVE_FUNCTION_TRACER
48d68b20 37 select HAVE_FUNCTION_GRAPH_TRACER
71e308a2 38 select HAVE_FUNCTION_GRAPH_FP_TEST
60a7ecf4 39 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
9a5fd902 40 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
1b3fa2ce 41 select HAVE_FTRACE_SYSCALLS
e0ec9483 42 select HAVE_KVM
49793b03 43 select HAVE_ARCH_KGDB
99bbc4b1 44 select HAVE_ARCH_TRACEHOOK
323ec001 45 select HAVE_GENERIC_DMA_COHERENT if X86_32
58340a07 46 select HAVE_EFFICIENT_UNALIGNED_ACCESS
8d26487f 47 select USER_STACKTRACE_SUPPORT
2118d0c5 48 select HAVE_DMA_API_DEBUG
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49 select HAVE_KERNEL_GZIP
50 select HAVE_KERNEL_BZIP2
51 select HAVE_KERNEL_LZMA
0a4af3b0 52 select HAVE_ARCH_KMEMCHECK
7d8330a5 53
51b26ada
LT
54config OUTPUT_FORMAT
55 string
56 default "elf32-i386" if X86_32
57 default "elf64-x86-64" if X86_64
58
73531905 59config ARCH_DEFCONFIG
b9b39bfb 60 string
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61 default "arch/x86/configs/i386_defconfig" if X86_32
62 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 63
8d5fffb9 64config GENERIC_TIME
3c2362e6 65 def_bool y
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SR
66
67config GENERIC_CMOS_UPDATE
3c2362e6 68 def_bool y
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69
70config CLOCKSOURCE_WATCHDOG
3c2362e6 71 def_bool y
8d5fffb9
SR
72
73config GENERIC_CLOCKEVENTS
3c2362e6 74 def_bool y
8d5fffb9
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75
76config GENERIC_CLOCKEVENTS_BROADCAST
3c2362e6 77 def_bool y
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78 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
79
80config LOCKDEP_SUPPORT
3c2362e6 81 def_bool y
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82
83config STACKTRACE_SUPPORT
3c2362e6 84 def_bool y
8d5fffb9 85
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86config HAVE_LATENCYTOP_SUPPORT
87 def_bool y
88
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89config FAST_CMPXCHG_LOCAL
90 bool
91 default y
92
8d5fffb9 93config MMU
3c2362e6 94 def_bool y
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95
96config ZONE_DMA
3c2362e6 97 def_bool y
8d5fffb9 98
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99config SBUS
100 bool
101
102config GENERIC_ISA_DMA
3c2362e6 103 def_bool y
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104
105config GENERIC_IOMAP
3c2362e6 106 def_bool y
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107
108config GENERIC_BUG
3c2362e6 109 def_bool y
8d5fffb9 110 depends on BUG
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111 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
112
113config GENERIC_BUG_RELATIVE_POINTERS
114 bool
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115
116config GENERIC_HWEIGHT
3c2362e6 117 def_bool y
8d5fffb9 118
a6082959 119config GENERIC_GPIO
9ba16087 120 bool
a6082959 121
8d5fffb9 122config ARCH_MAY_HAVE_PC_FDC
3c2362e6 123 def_bool y
8d5fffb9 124
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125config RWSEM_GENERIC_SPINLOCK
126 def_bool !X86_XADD
127
128config RWSEM_XCHGADD_ALGORITHM
129 def_bool X86_XADD
130
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131config ARCH_HAS_CPU_IDLE_WAIT
132 def_bool y
133
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134config GENERIC_CALIBRATE_DELAY
135 def_bool y
136
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137config GENERIC_TIME_VSYSCALL
138 bool
139 default X86_64
140
9a0b8415 141config ARCH_HAS_CPU_RELAX
142 def_bool y
143
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144config ARCH_HAS_DEFAULT_IDLE
145 def_bool y
146
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147config ARCH_HAS_CACHE_LINE_SIZE
148 def_bool y
149
dd5af90a 150config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 151 def_bool y
b32ef636 152
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153config HAVE_CPUMASK_OF_CPU_MAP
154 def_bool X86_64_SMP
155
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156config ARCH_HIBERNATION_POSSIBLE
157 def_bool y
801e4062 158
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159config ARCH_SUSPEND_POSSIBLE
160 def_bool y
f4cb5700 161
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162config ZONE_DMA32
163 bool
164 default X86_64
165
166config ARCH_POPULATES_NODE_MAP
167 def_bool y
168
169config AUDIT_ARCH
170 bool
171 default X86_64
172
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173config ARCH_SUPPORTS_OPTIMIZED_INLINING
174 def_bool y
175
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176config ARCH_SUPPORTS_DEBUG_PAGEALLOC
177 def_bool y
178
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179# Use the generic interrupt handling code in kernel/irq/:
180config GENERIC_HARDIRQS
181 bool
182 default y
183
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184config GENERIC_HARDIRQS_NO__DO_IRQ
185 def_bool y
186
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187config GENERIC_IRQ_PROBE
188 bool
189 default y
190
191config GENERIC_PENDING_IRQ
192 bool
193 depends on GENERIC_HARDIRQS && SMP
194 default y
195
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196config USE_GENERIC_SMP_HELPERS
197 def_bool y
198 depends on SMP
199
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200config X86_32_SMP
201 def_bool y
202 depends on X86_32 && SMP
203
204config X86_64_SMP
205 def_bool y
206 depends on X86_64 && SMP
207
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208config X86_HT
209 bool
ee0011a7 210 depends on SMP
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211 default y
212
213config X86_TRAMPOLINE
214 bool
3e5095d1 215 depends on SMP || (64BIT && ACPI_SLEEP)
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216 default y
217
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218config X86_32_LAZY_GS
219 def_bool y
60a5317f 220 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 221
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222config KTIME_SCALAR
223 def_bool X86_32
506f1d07 224source "init/Kconfig"
dc52ddc0 225source "kernel/Kconfig.freezer"
8d5fffb9 226
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227menu "Processor type and features"
228
229source "kernel/time/Kconfig"
230
231config SMP
232 bool "Symmetric multi-processing support"
233 ---help---
234 This enables support for systems with more than one CPU. If you have
235 a system with only one CPU, like most personal computers, say N. If
236 you have a system with more than one CPU, say Y.
237
238 If you say N here, the kernel will run on single and multiprocessor
239 machines, but will use only one CPU of a multiprocessor machine. If
240 you say Y here, the kernel will run on many, but not all,
241 singleprocessor machines. On a singleprocessor machine, the kernel
242 will run faster if you say N here.
243
244 Note that if you say Y here and choose architecture "586" or
245 "Pentium" under "Processor family", the kernel will not work on 486
246 architectures. Similarly, multiprocessor kernels for the "PPro"
247 architecture may not work on all Pentium based boards.
248
249 People using multiprocessor machines who say Y here should also say
250 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
251 Management" code will be disabled if you say Y here.
252
03502faa 253 See also <file:Documentation/i386/IO-APIC.txt>,
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254 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
255 <http://www.tldp.org/docs.html#howto>.
256
257 If you don't know what to do here, say N.
258
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259config X86_X2APIC
260 bool "Support x2apic"
f7d7f866 261 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
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262 ---help---
263 This enables x2apic support on CPUs that have this feature.
264
265 This allows 32-bit apic IDs (so it can support very large systems),
266 and accesses the local apic via MSRs not via mmio.
267
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268 If you don't know what to do here, say N.
269
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270config SPARSE_IRQ
271 bool "Support sparse irq numbering"
17483a1f 272 depends on PCI_MSI || HT_IRQ
8f9ca475 273 ---help---
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274 This enables support for sparse irqs. This is useful for distro
275 kernels that want to define a high CONFIG_NR_CPUS value but still
276 want to have low kernel memory footprint on smaller machines.
0b8f1efa 277
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278 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
279 out the irq_desc[] array in a more NUMA-friendly way. )
280
281 If you don't know what to do here, say N.
0b8f1efa 282
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283config NUMA_IRQ_DESC
284 def_bool y
b9098957 285 depends on SPARSE_IRQ && NUMA
48a1b10a 286
6695c85b 287config X86_MPPARSE
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288 bool "Enable MPS table" if ACPI
289 default y
5ab74722 290 depends on X86_LOCAL_APIC
8f9ca475 291 ---help---
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292 For old smp systems that do not have proper acpi support. Newer systems
293 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 294
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295config X86_BIGSMP
296 bool "Support for big SMP systems with more than 8 CPUs"
297 depends on X86_32 && SMP
8f9ca475 298 ---help---
26f7ef14 299 This option is needed for the systems that have more than 8 CPUs
506f1d07 300
8425091f 301if X86_32
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302config X86_EXTENDED_PLATFORM
303 bool "Support for extended (non-PC) x86 platforms"
304 default y
8f9ca475 305 ---help---
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306 If you disable this option then the kernel will only support
307 standard PC platforms. (which covers the vast majority of
308 systems out there.)
309
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310 If you enable this option then you'll be able to select support
311 for the following (non-PC) 32 bit x86 platforms:
312 AMD Elan
313 NUMAQ (IBM/Sequent)
314 RDC R-321x SoC
315 SGI 320/540 (Visual Workstation)
316 Summit/EXA (IBM x440)
317 Unisys ES7000 IA32 series
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318
319 If you have one of these systems, or if you want to build a
320 generic distribution kernel, say Y here - otherwise say N.
8425091f 321endif
06ac8346 322
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323if X86_64
324config X86_EXTENDED_PLATFORM
325 bool "Support for extended (non-PC) x86 platforms"
326 default y
327 ---help---
328 If you disable this option then the kernel will only support
329 standard PC platforms. (which covers the vast majority of
330 systems out there.)
331
332 If you enable this option then you'll be able to select support
333 for the following (non-PC) 64 bit x86 platforms:
334 ScaleMP vSMP
335 SGI Ultraviolet
336
337 If you have one of these systems, or if you want to build a
338 generic distribution kernel, say Y here - otherwise say N.
339endif
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340# This is an alphabetically sorted list of 64 bit extended platforms
341# Please maintain the alphabetic order if and when there are additions
506f1d07 342
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343config X86_VSMP
344 bool "ScaleMP vSMP"
345 select PARAVIRT
346 depends on X86_64 && PCI
347 depends on X86_EXTENDED_PLATFORM
8f9ca475 348 ---help---
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349 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
350 supposed to run on these EM64T-based machines. Only choose this option
351 if you have one of these machines.
5e3a77e9 352
03b48632
NP
353config X86_UV
354 bool "SGI Ultraviolet"
355 depends on X86_64
c5c606d9 356 depends on X86_EXTENDED_PLATFORM
54c28d29 357 depends on NUMA
9d6c26e7 358 depends on X86_X2APIC
8f9ca475 359 ---help---
03b48632
NP
360 This option is needed in order to support SGI Ultraviolet systems.
361 If you don't have one of these, you should say N here.
362
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363# Following is an alphabetically sorted list of 32 bit extended platforms
364# Please maintain the alphabetic order if and when there are additions
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365
366config X86_ELAN
367 bool "AMD Elan"
368 depends on X86_32
c5c606d9 369 depends on X86_EXTENDED_PLATFORM
8f9ca475 370 ---help---
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371 Select this for an AMD Elan processor.
372
373 Do not use this option for K6/Athlon/Opteron processors!
374
375 If unsure, choose "PC-compatible" instead.
376
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377config X86_RDC321X
378 bool "RDC R-321x SoC"
506f1d07 379 depends on X86_32
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380 depends on X86_EXTENDED_PLATFORM
381 select M486
382 select X86_REBOOTFIXUPS
383 ---help---
384 This option is needed for RDC R-321x system-on-chip, also known
385 as R-8610-(G).
386 If you don't have one of these chips, you should say N here.
387
e0c7ae37 388config X86_32_NON_STANDARD
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389 bool "Support non-standard 32-bit SMP architectures"
390 depends on X86_32 && SMP
c5c606d9 391 depends on X86_EXTENDED_PLATFORM
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392 ---help---
393 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
d49c4288
YL
394 subarchitectures. It is intended for a generic binary kernel.
395 if you select them all, kernel will probe it one by one. and will
396 fallback to default.
397
c5c606d9 398# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 399
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SR
400config X86_NUMAQ
401 bool "NUMAQ (IBM/Sequent)"
e0c7ae37 402 depends on X86_32_NON_STANDARD
506f1d07 403 select NUMA
9c398017 404 select X86_MPPARSE
8f9ca475 405 ---help---
d49c4288
YL
406 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
407 NUMA multiquad box. This changes the way that processors are
408 bootstrapped, and uses Clustered Logical APIC addressing mode instead
409 of Flat Logical. You will need a new lynxer.elf file to flash your
410 firmware with - send email to <Martin.Bligh@us.ibm.com>.
506f1d07 411
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412config X86_VISWS
413 bool "SGI 320/540 (Visual Workstation)"
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RT
414 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
415 depends on X86_32_NON_STANDARD
416 ---help---
1b84e1c8
IM
417 The SGI Visual Workstation series is an IA32-based workstation
418 based on SGI systems chips with some legacy PC hardware attached.
419
420 Say Y here to create a kernel to run on the SGI 320 or 540.
421
422 A kernel compiled for the Visual Workstation will run on general
423 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
424
9c398017
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425config X86_SUMMIT
426 bool "Summit/EXA (IBM x440)"
e0c7ae37 427 depends on X86_32_NON_STANDARD
8f9ca475 428 ---help---
9c398017
IM
429 This option is needed for IBM systems that use the Summit/EXA chipset.
430 In particular, it is needed for the x440.
1f972768 431
9c398017 432config X86_ES7000
c5c606d9 433 bool "Unisys ES7000 IA32 series"
26f7ef14 434 depends on X86_32_NON_STANDARD && X86_BIGSMP
8f9ca475 435 ---help---
9c398017
IM
436 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
437 supposed to run on an IA32-based Unisys ES7000 system.
438
ae1e9130 439config SCHED_OMIT_FRAME_POINTER
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HH
440 def_bool y
441 prompt "Single-depth WCHAN output"
a87d0914 442 depends on X86
8f9ca475 443 ---help---
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444 Calculate simpler /proc/<PID>/wchan values. If this option
445 is disabled then wchan values will recurse back to the
446 caller function. This provides more accurate wchan values,
447 at the expense of slightly more scheduling overhead.
448
449 If in doubt, say "Y".
450
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451menuconfig PARAVIRT_GUEST
452 bool "Paravirtualized guest support"
8f9ca475 453 ---help---
506f1d07
SR
454 Say Y here to get to see options related to running Linux under
455 various hypervisors. This option alone does not add any kernel code.
456
457 If you say N, all options in this submenu will be skipped and disabled.
458
459if PARAVIRT_GUEST
460
461source "arch/x86/xen/Kconfig"
462
463config VMI
464 bool "VMI Guest support"
465 select PARAVIRT
42d545c9 466 depends on X86_32
8f9ca475 467 ---help---
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468 VMI provides a paravirtualized interface to the VMware ESX server
469 (it could be used by other hypervisors in theory too, but is not
470 at the moment), by linking the kernel to a GPL-ed ROM module
471 provided by the hypervisor.
472
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473config KVM_CLOCK
474 bool "KVM paravirtualized clock"
475 select PARAVIRT
f6e16d5a 476 select PARAVIRT_CLOCK
8f9ca475 477 ---help---
790c73f6
GOC
478 Turning on this option will allow you to run a paravirtualized clock
479 when running over the KVM hypervisor. Instead of relying on a PIT
480 (or probably other) emulation by the underlying device model, the host
481 provides the guest with timing infrastructure such as time of day, and
482 system time
483
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484config KVM_GUEST
485 bool "KVM Guest support"
486 select PARAVIRT
8f9ca475
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487 ---help---
488 This option enables various optimizations for running under the KVM
489 hypervisor.
0cf1bfd2 490
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491source "arch/x86/lguest/Kconfig"
492
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493config PARAVIRT
494 bool "Enable paravirtualization code"
8f9ca475 495 ---help---
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496 This changes the kernel so it can modify itself when it is run
497 under a hypervisor, potentially improving performance significantly
498 over full virtualization. However, when run without a hypervisor
499 the kernel is theoretically slower and slightly larger.
500
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JF
501config PARAVIRT_SPINLOCKS
502 bool "Paravirtualization layer for spinlocks"
503 depends on PARAVIRT && SMP && EXPERIMENTAL
504 ---help---
505 Paravirtualized spinlocks allow a pvops backend to replace the
506 spinlock implementation with something virtualization-friendly
507 (for example, block the virtual CPU rather than spinning).
508
509 Unfortunately the downside is an up to 5% performance hit on
510 native kernels, with various workloads.
511
512 If you are unsure how to answer this question, answer N.
513
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GH
514config PARAVIRT_CLOCK
515 bool
516 default n
517
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SR
518endif
519
97349135 520config PARAVIRT_DEBUG
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521 bool "paravirt-ops debugging"
522 depends on PARAVIRT && DEBUG_KERNEL
523 ---help---
524 Enable to debug paravirt_ops internals. Specifically, BUG if
525 a paravirt_op is missing when it is called.
97349135 526
03273184
YL
527config MEMTEST
528 bool "Memtest"
8f9ca475 529 ---help---
c64df707 530 This option adds a kernel parameter 'memtest', which allows memtest
03273184 531 to be set.
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IM
532 memtest=0, mean disabled; -- default
533 memtest=1, mean do 1 test pattern;
534 ...
535 memtest=4, mean do 4 test patterns.
aba3728c 536 If you are unsure how to answer this question, answer N.
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SR
537
538config X86_SUMMIT_NUMA
3c2362e6 539 def_bool y
e0c7ae37 540 depends on X86_32 && NUMA && X86_32_NON_STANDARD
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SR
541
542config X86_CYCLONE_TIMER
3c2362e6 543 def_bool y
e0c7ae37 544 depends on X86_32_NON_STANDARD
506f1d07 545
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SR
546source "arch/x86/Kconfig.cpu"
547
548config HPET_TIMER
3c2362e6 549 def_bool X86_64
506f1d07 550 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
551 ---help---
552 Use the IA-PC HPET (High Precision Event Timer) to manage
553 time in preference to the PIT and RTC, if a HPET is
554 present.
555 HPET is the next generation timer replacing legacy 8254s.
556 The HPET provides a stable time base on SMP
557 systems, unlike the TSC, but it is more expensive to access,
558 as it is off-chip. You can find the HPET spec at
559 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
506f1d07 560
8f9ca475
IM
561 You can safely choose Y here. However, HPET will only be
562 activated if the platform and the BIOS support this feature.
563 Otherwise the 8254 will be used for timing services.
506f1d07 564
8f9ca475 565 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
566
567config HPET_EMULATE_RTC
3c2362e6 568 def_bool y
9d8af78b 569 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
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SR
570
571# Mark as embedded because too many people got it wrong.
572# The code disables itself when not needed.
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573config DMI
574 default y
575 bool "Enable DMI scanning" if EMBEDDED
8f9ca475 576 ---help---
7ae9392c
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577 Enabled scanning of DMI to identify machine quirks. Say Y
578 here unless you have verified that your setup is not
579 affected by entries in the DMI blacklist. Required by PNP
580 BIOS code.
581
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SR
582config GART_IOMMU
583 bool "GART IOMMU support" if EMBEDDED
584 default y
585 select SWIOTLB
586 select AGP
587 depends on X86_64 && PCI
8f9ca475 588 ---help---
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SR
589 Support for full DMA access of devices with 32bit memory access only
590 on systems with more than 3GB. This is usually needed for USB,
591 sound, many IDE/SATA chipsets and some other devices.
592 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
593 based hardware IOMMU and a software bounce buffer based IOMMU used
594 on Intel systems and as fallback.
595 The code is only active when needed (enough memory and limited
596 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
597 too.
598
599config CALGARY_IOMMU
600 bool "IBM Calgary IOMMU support"
601 select SWIOTLB
602 depends on X86_64 && PCI && EXPERIMENTAL
8f9ca475 603 ---help---
506f1d07
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604 Support for hardware IOMMUs in IBM's xSeries x366 and x460
605 systems. Needed to run systems with more than 3GB of memory
606 properly with 32-bit PCI devices that do not support DAC
607 (Double Address Cycle). Calgary also supports bus level
608 isolation, where all DMAs pass through the IOMMU. This
609 prevents them from going anywhere except their intended
610 destination. This catches hard-to-find kernel bugs and
611 mis-behaving drivers and devices that do not use the DMA-API
612 properly to set up their DMA buffers. The IOMMU can be
613 turned off at boot time with the iommu=off parameter.
614 Normally the kernel will make the right choice by itself.
615 If unsure, say Y.
616
617config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
618 def_bool y
619 prompt "Should Calgary be enabled by default?"
506f1d07 620 depends on CALGARY_IOMMU
8f9ca475 621 ---help---
506f1d07
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622 Should Calgary be enabled by default? if you choose 'y', Calgary
623 will be used (if it exists). If you choose 'n', Calgary will not be
624 used even if it exists. If you choose 'n' and would like to use
625 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
626 If unsure, say Y.
627
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628config AMD_IOMMU
629 bool "AMD IOMMU support"
07c40e8a 630 select SWIOTLB
a80dc3e0 631 select PCI_MSI
24d2ba0a 632 depends on X86_64 && PCI && ACPI
8f9ca475 633 ---help---
18d22200
JR
634 With this option you can enable support for AMD IOMMU hardware in
635 your system. An IOMMU is a hardware component which provides
636 remapping of DMA memory accesses from devices. With an AMD IOMMU you
637 can isolate the the DMA memory of different devices and protect the
638 system from misbehaving device drivers or hardware.
639
640 You can find out if your system has an AMD IOMMU if you look into
641 your BIOS for an option to enable it or if you have an IVRS ACPI
642 table.
2b188723 643
2e117604
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644config AMD_IOMMU_STATS
645 bool "Export AMD IOMMU statistics to debugfs"
646 depends on AMD_IOMMU
647 select DEBUG_FS
8f9ca475 648 ---help---
2e117604
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649 This option enables code in the AMD IOMMU driver to collect various
650 statistics about whats happening in the driver and exports that
651 information to userspace via debugfs.
652 If unsure, say N.
653
506f1d07
SR
654# need this always selected by IOMMU for the VIA workaround
655config SWIOTLB
a1afd01c 656 def_bool y if X86_64
8f9ca475 657 ---help---
506f1d07
SR
658 Support for software bounce buffers used on x86-64 systems
659 which don't have a hardware IOMMU (e.g. the current generation
660 of Intel's x86-64 CPUs). Using this PCI devices which can only
661 access 32-bits of memory can be used on systems with more than
662 3 GB of memory. If unsure, say Y.
663
a8522509 664config IOMMU_HELPER
18b743dc 665 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
d25e26b6 666
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667config IOMMU_API
668 def_bool (AMD_IOMMU || DMAR)
669
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MT
670config MAXSMP
671 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
36f5101a
MT
672 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
673 select CPUMASK_OFFSTACK
1184dc2f 674 default n
8f9ca475 675 ---help---
1184dc2f
MT
676 Configure maximum number of CPUS and NUMA Nodes for this architecture.
677 If unsure, say N.
506f1d07
SR
678
679config NR_CPUS
36f5101a 680 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 681 range 2 8 if SMP && X86_32 && !X86_BIGSMP
36f5101a 682 range 2 512 if SMP && !MAXSMP
78637a97 683 default "1" if !SMP
d25e26b6 684 default "4096" if MAXSMP
78637a97
MT
685 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
686 default "8" if SMP
8f9ca475 687 ---help---
506f1d07 688 This allows you to specify the maximum number of CPUs which this
d25e26b6 689 kernel will support. The maximum supported value is 512 and the
506f1d07
SR
690 minimum value which makes sense is 2.
691
692 This is purely to save memory - each supported CPU adds
693 approximately eight kilobytes to the kernel image.
694
695config SCHED_SMT
696 bool "SMT (Hyperthreading) scheduler support"
b089c12b 697 depends on X86_HT
8f9ca475 698 ---help---
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SR
699 SMT scheduler support improves the CPU scheduler's decision making
700 when dealing with Intel Pentium 4 chips with HyperThreading at a
701 cost of slightly increased overhead in some places. If unsure say
702 N here.
703
704config SCHED_MC
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HH
705 def_bool y
706 prompt "Multi-core scheduler support"
b089c12b 707 depends on X86_HT
8f9ca475 708 ---help---
506f1d07
SR
709 Multi-core scheduler support improves the CPU scheduler's decision
710 making when dealing with multi-core CPU chips at a cost of slightly
711 increased overhead in some places. If unsure say N here.
712
713source "kernel/Kconfig.preempt"
714
715config X86_UP_APIC
716 bool "Local APIC support on uniprocessors"
e0c7ae37 717 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 718 ---help---
506f1d07
SR
719 A local APIC (Advanced Programmable Interrupt Controller) is an
720 integrated interrupt controller in the CPU. If you have a single-CPU
721 system which has a processor with a local APIC, you can say Y here to
722 enable and use it. If you say Y here even though your machine doesn't
723 have a local APIC, then the kernel will still run with no slowdown at
724 all. The local APIC supports CPU-generated self-interrupts (timer,
725 performance counters), and the NMI watchdog which detects hard
726 lockups.
727
728config X86_UP_IOAPIC
729 bool "IO-APIC support on uniprocessors"
730 depends on X86_UP_APIC
8f9ca475 731 ---help---
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SR
732 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
733 SMP-capable replacement for PC-style interrupt controllers. Most
734 SMP systems and many recent uniprocessor systems have one.
735
736 If you have a single-CPU system with an IO-APIC, you can say Y here
737 to use it. If you say Y here even though your machine doesn't have
738 an IO-APIC, then the kernel will still run with no slowdown at all.
739
740config X86_LOCAL_APIC
3c2362e6 741 def_bool y
e0c7ae37 742 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
506f1d07
SR
743
744config X86_IO_APIC
3c2362e6 745 def_bool y
e0c7ae37 746 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
506f1d07
SR
747
748config X86_VISWS_APIC
3c2362e6 749 def_bool y
506f1d07 750 depends on X86_32 && X86_VISWS
506f1d07 751
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SA
752config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
753 bool "Reroute for broken boot IRQs"
754 default n
755 depends on X86_IO_APIC
8f9ca475 756 ---help---
41b9eb26
SA
757 This option enables a workaround that fixes a source of
758 spurious interrupts. This is recommended when threaded
759 interrupt handling is used on systems where the generation of
760 superfluous "boot interrupts" cannot be disabled.
761
762 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
763 entry in the chipset's IO-APIC is masked (as, e.g. the RT
764 kernel does during interrupt handling). On chipsets where this
765 boot IRQ generation cannot be disabled, this workaround keeps
766 the original IRQ line masked so that only the equivalent "boot
767 IRQ" is delivered to the CPUs. The workaround also tells the
768 kernel to set up the IRQ handler on the boot IRQ line. In this
769 way only one interrupt is delivered to the kernel. Otherwise
770 the spurious second interrupt may cause the kernel to bring
771 down (vital) interrupt lines.
772
773 Only affects "broken" chipsets. Interrupt sharing may be
774 increased on these systems.
775
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SR
776config X86_MCE
777 bool "Machine Check Exception"
506f1d07
SR
778 ---help---
779 Machine Check Exception support allows the processor to notify the
780 kernel if it detects a problem (e.g. overheating, component failure).
781 The action the kernel takes depends on the severity of the problem,
782 ranging from a warning message on the console, to halting the machine.
783 Your processor must be a Pentium or newer to support this - check the
784 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
785 have a design flaw which leads to false MCE events - hence MCE is
786 disabled on all P5 processors, unless explicitly enabled with "mce"
787 as a boot argument. Similarly, if MCE is built in and creates a
788 problem on some new non-standard machine, you can boot with "nomce"
789 to disable it. MCE support simply ignores non-MCE processors like
790 the 386 and 486, so nearly everyone can say Y here.
791
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792config X86_OLD_MCE
793 depends on X86_32 && X86_MCE
794 bool "Use legacy machine check code (will go away)"
795 default n
796 select X86_ANCIENT_MCE
797 ---help---
798 Use the old i386 machine check code. This is merely intended for
799 testing in a transition period. Try this if you run into any machine
800 check related software problems, but report the problem to
801 linux-kernel. When in doubt say no.
802
803config X86_NEW_MCE
804 depends on X86_MCE
805 bool
806 default y if (!X86_OLD_MCE && X86_32) || X86_64
807
506f1d07 808config X86_MCE_INTEL
3c2362e6
HH
809 def_bool y
810 prompt "Intel MCE features"
7856f6cc 811 depends on X86_NEW_MCE && X86_LOCAL_APIC
8f9ca475 812 ---help---
506f1d07
SR
813 Additional support for intel specific MCE features such as
814 the thermal monitor.
815
816config X86_MCE_AMD
3c2362e6
HH
817 def_bool y
818 prompt "AMD MCE features"
de5619df 819 depends on X86_NEW_MCE && X86_LOCAL_APIC
8f9ca475 820 ---help---
506f1d07
SR
821 Additional support for AMD specific MCE features such as
822 the DRAM Error Threshold.
823
4efc0670 824config X86_ANCIENT_MCE
cd13adcc
HS
825 def_bool n
826 depends on X86_32
827 prompt "Support for old Pentium 5 / WinChip machine checks"
828 ---help---
829 Include support for machine check handling on old Pentium 5 or WinChip
830 systems. These typically need to be enabled explicitely on the command
831 line.
4efc0670 832
b2762686
AK
833config X86_MCE_THRESHOLD
834 depends on X86_MCE_AMD || X86_MCE_INTEL
835 bool
836 default y
837
ea149b36
AK
838config X86_MCE_INJECT
839 depends on X86_NEW_MCE
840 tristate "Machine check injector support"
841 ---help---
842 Provide support for injecting machine checks for testing purposes.
843 If you don't know what a machine check is and you don't do kernel
844 QA it is safe to say n.
845
506f1d07
SR
846config X86_MCE_NONFATAL
847 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
4efc0670 848 depends on X86_OLD_MCE
8f9ca475 849 ---help---
506f1d07
SR
850 Enabling this feature starts a timer that triggers every 5 seconds which
851 will look at the machine check registers to see if anything happened.
852 Non-fatal problems automatically get corrected (but still logged).
853 Disable this if you don't want to see these messages.
854 Seeing the messages this option prints out may be indicative of dying
855 or out-of-spec (ie, overclocked) hardware.
856 This option only does something on certain CPUs.
857 (AMD Athlon/Duron and Intel Pentium 4)
858
859config X86_MCE_P4THERMAL
860 bool "check for P4 thermal throttling interrupt."
4efc0670 861 depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
8f9ca475 862 ---help---
506f1d07
SR
863 Enabling this feature will cause a message to be printed when the P4
864 enters thermal throttling.
865
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AK
866config X86_THERMAL_VECTOR
867 def_bool y
868 depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
869
506f1d07
SR
870config VM86
871 bool "Enable VM86 support" if EMBEDDED
872 default y
873 depends on X86_32
8f9ca475
IM
874 ---help---
875 This option is required by programs like DOSEMU to run 16-bit legacy
506f1d07 876 code on X86 processors. It also may be needed by software like
8f9ca475
IM
877 XFree86 to initialize some video cards via BIOS. Disabling this
878 option saves about 6k.
506f1d07
SR
879
880config TOSHIBA
881 tristate "Toshiba Laptop support"
882 depends on X86_32
883 ---help---
884 This adds a driver to safely access the System Management Mode of
885 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
886 not work on models with a Phoenix BIOS. The System Management Mode
887 is used to set the BIOS and power saving options on Toshiba portables.
888
889 For information on utilities to make use of this driver see the
890 Toshiba Linux utilities web site at:
891 <http://www.buzzard.org.uk/toshiba/>.
892
893 Say Y if you intend to run this kernel on a Toshiba portable.
894 Say N otherwise.
895
896config I8K
897 tristate "Dell laptop support"
506f1d07
SR
898 ---help---
899 This adds a driver to safely access the System Management Mode
900 of the CPU on the Dell Inspiron 8000. The System Management Mode
901 is used to read cpu temperature and cooling fan status and to
902 control the fans on the I8K portables.
903
904 This driver has been tested only on the Inspiron 8000 but it may
905 also work with other Dell laptops. You can force loading on other
906 models by passing the parameter `force=1' to the module. Use at
907 your own risk.
908
909 For information on utilities to make use of this driver see the
910 I8K Linux utilities web site at:
911 <http://people.debian.org/~dz/i8k/>
912
913 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
914 Say N otherwise.
915
916config X86_REBOOTFIXUPS
9ba16087
JB
917 bool "Enable X86 board specific fixups for reboot"
918 depends on X86_32
506f1d07
SR
919 ---help---
920 This enables chipset and/or board specific fixups to be done
921 in order to get reboot to work correctly. This is only needed on
922 some combinations of hardware and BIOS. The symptom, for which
923 this config is intended, is when reboot ends with a stalled/hung
924 system.
925
926 Currently, the only fixup is for the Geode machines using
5e3a77e9 927 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
928
929 Say Y if you want to enable the fixup. Currently, it's safe to
930 enable this option even if you don't need it.
931 Say N otherwise.
932
933config MICROCODE
8d86f390 934 tristate "/dev/cpu/microcode - microcode support"
506f1d07
SR
935 select FW_LOADER
936 ---help---
937 If you say Y here, you will be able to update the microcode on
80cc9f10
PO
938 certain Intel and AMD processors. The Intel support is for the
939 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
940 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
941 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
942 You will obviously need the actual microcode binary data itself
943 which is not shipped with the Linux kernel.
506f1d07 944
8d86f390
PO
945 This option selects the general module only, you need to select
946 at least one vendor specific module as well.
506f1d07
SR
947
948 To compile this driver as a module, choose M here: the
949 module will be called microcode.
950
8d86f390 951config MICROCODE_INTEL
8f9ca475
IM
952 bool "Intel microcode patch loading support"
953 depends on MICROCODE
954 default MICROCODE
955 select FW_LOADER
956 ---help---
957 This options enables microcode patch loading support for Intel
958 processors.
959
960 For latest news and information on obtaining all the required
961 Intel ingredients for this driver, check:
962 <http://www.urbanmyth.org/microcode/>.
8d86f390 963
80cc9f10 964config MICROCODE_AMD
8f9ca475
IM
965 bool "AMD microcode patch loading support"
966 depends on MICROCODE
967 select FW_LOADER
968 ---help---
969 If you select this option, microcode patch loading support for AMD
970 processors will be enabled.
80cc9f10 971
8f9ca475 972config MICROCODE_OLD_INTERFACE
3c2362e6 973 def_bool y
506f1d07 974 depends on MICROCODE
506f1d07
SR
975
976config X86_MSR
977 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 978 ---help---
506f1d07
SR
979 This device gives privileged processes access to the x86
980 Model-Specific Registers (MSRs). It is a character device with
981 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
982 MSR accesses are directed to a specific CPU on multi-processor
983 systems.
984
985config X86_CPUID
986 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 987 ---help---
506f1d07
SR
988 This device gives processes access to the x86 CPUID instruction to
989 be executed on a specific processor. It is a character device
990 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
991 /dev/cpu/31/cpuid.
992
9b779edf
JSR
993config X86_CPU_DEBUG
994 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
995 ---help---
996 If you select this option, this will provide various x86 CPUs
997 information through debugfs.
998
506f1d07
SR
999choice
1000 prompt "High Memory Support"
1001 default HIGHMEM4G if !X86_NUMAQ
1002 default HIGHMEM64G if X86_NUMAQ
1003 depends on X86_32
1004
1005config NOHIGHMEM
1006 bool "off"
1007 depends on !X86_NUMAQ
1008 ---help---
1009 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1010 However, the address space of 32-bit x86 processors is only 4
1011 Gigabytes large. That means that, if you have a large amount of
1012 physical memory, not all of it can be "permanently mapped" by the
1013 kernel. The physical memory that's not permanently mapped is called
1014 "high memory".
1015
1016 If you are compiling a kernel which will never run on a machine with
1017 more than 1 Gigabyte total physical RAM, answer "off" here (default
1018 choice and suitable for most users). This will result in a "3GB/1GB"
1019 split: 3GB are mapped so that each process sees a 3GB virtual memory
1020 space and the remaining part of the 4GB virtual memory space is used
1021 by the kernel to permanently map as much physical memory as
1022 possible.
1023
1024 If the machine has between 1 and 4 Gigabytes physical RAM, then
1025 answer "4GB" here.
1026
1027 If more than 4 Gigabytes is used then answer "64GB" here. This
1028 selection turns Intel PAE (Physical Address Extension) mode on.
1029 PAE implements 3-level paging on IA32 processors. PAE is fully
1030 supported by Linux, PAE mode is implemented on all recent Intel
1031 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1032 then the kernel will not boot on CPUs that don't support PAE!
1033
1034 The actual amount of total physical memory will either be
1035 auto detected or can be forced by using a kernel command line option
1036 such as "mem=256M". (Try "man bootparam" or see the documentation of
1037 your boot loader (lilo or loadlin) about how to pass options to the
1038 kernel at boot time.)
1039
1040 If unsure, say "off".
1041
1042config HIGHMEM4G
1043 bool "4GB"
1044 depends on !X86_NUMAQ
8f9ca475 1045 ---help---
506f1d07
SR
1046 Select this if you have a 32-bit processor and between 1 and 4
1047 gigabytes of physical RAM.
1048
1049config HIGHMEM64G
1050 bool "64GB"
1051 depends on !M386 && !M486
1052 select X86_PAE
8f9ca475 1053 ---help---
506f1d07
SR
1054 Select this if you have a 32-bit processor and more than 4
1055 gigabytes of physical RAM.
1056
1057endchoice
1058
1059choice
1060 depends on EXPERIMENTAL
1061 prompt "Memory split" if EMBEDDED
1062 default VMSPLIT_3G
1063 depends on X86_32
8f9ca475 1064 ---help---
506f1d07
SR
1065 Select the desired split between kernel and user memory.
1066
1067 If the address range available to the kernel is less than the
1068 physical memory installed, the remaining memory will be available
1069 as "high memory". Accessing high memory is a little more costly
1070 than low memory, as it needs to be mapped into the kernel first.
1071 Note that increasing the kernel address space limits the range
1072 available to user programs, making the address space there
1073 tighter. Selecting anything other than the default 3G/1G split
1074 will also likely make your kernel incompatible with binary-only
1075 kernel modules.
1076
1077 If you are not absolutely sure what you are doing, leave this
1078 option alone!
1079
1080 config VMSPLIT_3G
1081 bool "3G/1G user/kernel split"
1082 config VMSPLIT_3G_OPT
1083 depends on !X86_PAE
1084 bool "3G/1G user/kernel split (for full 1G low memory)"
1085 config VMSPLIT_2G
1086 bool "2G/2G user/kernel split"
1087 config VMSPLIT_2G_OPT
1088 depends on !X86_PAE
1089 bool "2G/2G user/kernel split (for full 2G low memory)"
1090 config VMSPLIT_1G
1091 bool "1G/3G user/kernel split"
1092endchoice
1093
1094config PAGE_OFFSET
1095 hex
1096 default 0xB0000000 if VMSPLIT_3G_OPT
1097 default 0x80000000 if VMSPLIT_2G
1098 default 0x78000000 if VMSPLIT_2G_OPT
1099 default 0x40000000 if VMSPLIT_1G
1100 default 0xC0000000
1101 depends on X86_32
1102
1103config HIGHMEM
3c2362e6 1104 def_bool y
506f1d07 1105 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1106
1107config X86_PAE
9ba16087 1108 bool "PAE (Physical Address Extension) Support"
506f1d07 1109 depends on X86_32 && !HIGHMEM4G
8f9ca475 1110 ---help---
506f1d07
SR
1111 PAE is required for NX support, and furthermore enables
1112 larger swapspace support for non-overcommit purposes. It
1113 has the cost of more pagetable lookup overhead, and also
1114 consumes more pagetable space per process.
1115
600715dc 1116config ARCH_PHYS_ADDR_T_64BIT
8f9ca475 1117 def_bool X86_64 || X86_PAE
600715dc 1118
9e899816
NP
1119config DIRECT_GBPAGES
1120 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1121 default y
1122 depends on X86_64
8f9ca475 1123 ---help---
9e899816
NP
1124 Allow the kernel linear mapping to use 1GB pages on CPUs that
1125 support it. This can improve the kernel's performance a tiny bit by
1126 reducing TLB pressure. If in doubt, say "Y".
1127
506f1d07
SR
1128# Common NUMA Features
1129config NUMA
fd51b2d7 1130 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1131 depends on SMP
604d2055 1132 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
0699eae1 1133 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
8f9ca475 1134 ---help---
506f1d07 1135 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1136
506f1d07
SR
1137 The kernel will try to allocate memory used by a CPU on the
1138 local memory controller of the CPU and add some more
1139 NUMA awareness to the kernel.
1140
c280ea5e 1141 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1142 (or later), AMD Opteron, or EM64T NUMA.
1143
1144 For 32-bit this is only needed on (rare) 32-bit-only platforms
1145 that support NUMA topologies, such as NUMAQ / Summit, or if you
1146 boot a 32-bit kernel on a 64-bit NUMA platform.
1147
1148 Otherwise, you should say N.
506f1d07
SR
1149
1150comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1151 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1152
1153config K8_NUMA
3c2362e6
HH
1154 def_bool y
1155 prompt "Old style AMD Opteron NUMA detection"
1156 depends on X86_64 && NUMA && PCI
8f9ca475
IM
1157 ---help---
1158 Enable K8 NUMA node topology detection. You should say Y here if
1159 you have a multi processor AMD K8 system. This uses an old
1160 method to read the NUMA configuration directly from the builtin
1161 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1162 instead, which also takes priority if both are compiled in.
506f1d07
SR
1163
1164config X86_64_ACPI_NUMA
3c2362e6
HH
1165 def_bool y
1166 prompt "ACPI NUMA detection"
506f1d07
SR
1167 depends on X86_64 && NUMA && ACPI && PCI
1168 select ACPI_NUMA
8f9ca475 1169 ---help---
506f1d07
SR
1170 Enable ACPI SRAT based node topology detection.
1171
6ec6e0d9
SS
1172# Some NUMA nodes have memory ranges that span
1173# other nodes. Even though a pfn is valid and
1174# between a node's start and end pfns, it may not
1175# reside on that node. See memmap_init_zone()
1176# for details.
1177config NODES_SPAN_OTHER_NODES
1178 def_bool y
1179 depends on X86_64_ACPI_NUMA
1180
506f1d07
SR
1181config NUMA_EMU
1182 bool "NUMA emulation"
1183 depends on X86_64 && NUMA
8f9ca475 1184 ---help---
506f1d07
SR
1185 Enable NUMA emulation. A flat machine will be split
1186 into virtual nodes when booted with "numa=fake=N", where N is the
1187 number of nodes. This is only useful for debugging.
1188
1189config NODES_SHIFT
d25e26b6 1190 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
46d50c98 1191 range 1 9
d25e26b6 1192 default "9" if MAXSMP
506f1d07
SR
1193 default "6" if X86_64
1194 default "4" if X86_NUMAQ
1195 default "3"
1196 depends on NEED_MULTIPLE_NODES
8f9ca475 1197 ---help---
1184dc2f 1198 Specify the maximum number of NUMA Nodes available on the target
692105b8 1199 system. Increases memory reserved to accommodate various tables.
506f1d07 1200
c1329375 1201config HAVE_ARCH_BOOTMEM
3c2362e6 1202 def_bool y
506f1d07 1203 depends on X86_32 && NUMA
506f1d07
SR
1204
1205config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1206 def_bool y
506f1d07 1207 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1208
1209config NEED_NODE_MEMMAP_SIZE
3c2362e6 1210 def_bool y
506f1d07 1211 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07
SR
1212
1213config HAVE_ARCH_ALLOC_REMAP
3c2362e6 1214 def_bool y
506f1d07 1215 depends on X86_32 && NUMA
506f1d07
SR
1216
1217config ARCH_FLATMEM_ENABLE
1218 def_bool y
99809963 1219 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
506f1d07
SR
1220
1221config ARCH_DISCONTIGMEM_ENABLE
1222 def_bool y
b263295d 1223 depends on NUMA && X86_32
506f1d07
SR
1224
1225config ARCH_DISCONTIGMEM_DEFAULT
1226 def_bool y
b263295d
CL
1227 depends on NUMA && X86_32
1228
1229config ARCH_SPARSEMEM_DEFAULT
1230 def_bool y
1231 depends on X86_64
506f1d07
SR
1232
1233config ARCH_SPARSEMEM_ENABLE
1234 def_bool y
4272ebfb 1235 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
506f1d07
SR
1236 select SPARSEMEM_STATIC if X86_32
1237 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1238
1239config ARCH_SELECT_MEMORY_MODEL
1240 def_bool y
b263295d 1241 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1242
1243config ARCH_MEMORY_PROBE
1244 def_bool X86_64
1245 depends on MEMORY_HOTPLUG
1246
1247source "mm/Kconfig"
1248
1249config HIGHPTE
1250 bool "Allocate 3rd-level pagetables from highmem"
1251 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
8f9ca475 1252 ---help---
506f1d07
SR
1253 The VM uses one page table entry for each page of physical memory.
1254 For systems with a lot of RAM, this can be wasteful of precious
1255 low memory. Setting this option will put user-space page table
1256 entries in high memory.
1257
9f077871 1258config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1259 bool "Check for low memory corruption"
1260 ---help---
1261 Periodically check for memory corruption in low memory, which
1262 is suspected to be caused by BIOS. Even when enabled in the
1263 configuration, it is disabled at runtime. Enable it by
1264 setting "memory_corruption_check=1" on the kernel command
1265 line. By default it scans the low 64k of memory every 60
1266 seconds; see the memory_corruption_check_size and
1267 memory_corruption_check_period parameters in
1268 Documentation/kernel-parameters.txt to adjust this.
1269
1270 When enabled with the default parameters, this option has
1271 almost no overhead, as it reserves a relatively small amount
1272 of memory and scans it infrequently. It both detects corruption
1273 and prevents it from affecting the running system.
1274
1275 It is, however, intended as a diagnostic tool; if repeatable
1276 BIOS-originated corruption always affects the same memory,
1277 you can use memmap= to prevent the kernel from using that
1278 memory.
9f077871 1279
c885df50 1280config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1281 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1282 depends on X86_CHECK_BIOS_CORRUPTION
1283 default y
8f9ca475
IM
1284 ---help---
1285 Set whether the default state of memory_corruption_check is
1286 on or off.
c885df50 1287
fc381519 1288config X86_RESERVE_LOW_64K
8f9ca475 1289 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
fc381519 1290 default y
8f9ca475
IM
1291 ---help---
1292 Reserve the first 64K of physical RAM on BIOSes that are known
1293 to potentially corrupt that memory range. A numbers of BIOSes are
1294 known to utilize this area during suspend/resume, so it must not
1295 be used by the kernel.
fc381519 1296
8f9ca475
IM
1297 Set this to N if you are absolutely sure that you trust the BIOS
1298 to get all its memory reservations and usages right.
fc381519 1299
8f9ca475
IM
1300 If you have doubts about the BIOS (e.g. suspend/resume does not
1301 work or there's kernel crashes after certain hardware hotplug
1302 events) and it's not AMI or Phoenix, then you might want to enable
1303 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1304 corruption patterns.
fc381519 1305
8f9ca475 1306 Say Y if unsure.
fc381519 1307
506f1d07
SR
1308config MATH_EMULATION
1309 bool
1310 prompt "Math emulation" if X86_32
1311 ---help---
1312 Linux can emulate a math coprocessor (used for floating point
1313 operations) if you don't have one. 486DX and Pentium processors have
1314 a math coprocessor built in, 486SX and 386 do not, unless you added
1315 a 487DX or 387, respectively. (The messages during boot time can
1316 give you some hints here ["man dmesg"].) Everyone needs either a
1317 coprocessor or this emulation.
1318
1319 If you don't have a math coprocessor, you need to say Y here; if you
1320 say Y here even though you have a coprocessor, the coprocessor will
1321 be used nevertheless. (This behavior can be changed with the kernel
1322 command line option "no387", which comes handy if your coprocessor
1323 is broken. Try "man bootparam" or see the documentation of your boot
1324 loader (lilo or loadlin) about how to pass options to the kernel at
1325 boot time.) This means that it is a good idea to say Y here if you
1326 intend to use this kernel on different machines.
1327
1328 More information about the internals of the Linux math coprocessor
1329 emulation can be found in <file:arch/x86/math-emu/README>.
1330
1331 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1332 kernel, it won't hurt.
1333
1334config MTRR
1335 bool "MTRR (Memory Type Range Register) support"
1336 ---help---
1337 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1338 the Memory Type Range Registers (MTRRs) may be used to control
1339 processor access to memory ranges. This is most useful if you have
1340 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1341 allows bus write transfers to be combined into a larger transfer
1342 before bursting over the PCI/AGP bus. This can increase performance
1343 of image write operations 2.5 times or more. Saying Y here creates a
1344 /proc/mtrr file which may be used to manipulate your processor's
1345 MTRRs. Typically the X server should use this.
1346
1347 This code has a reasonably generic interface so that similar
1348 control registers on other processors can be easily supported
1349 as well:
1350
1351 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1352 Registers (ARRs) which provide a similar functionality to MTRRs. For
1353 these, the ARRs are used to emulate the MTRRs.
1354 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1355 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1356 write-combining. All of these processors are supported by this code
1357 and it makes sense to say Y here if you have one of them.
1358
1359 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1360 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1361 can lead to all sorts of problems, so it's good to say Y here.
1362
1363 You can safely say Y even if your machine doesn't have MTRRs, you'll
1364 just add about 9 KB to your kernel.
1365
7225e751 1366 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1367
95ffa243 1368config MTRR_SANITIZER
2ffb3501 1369 def_bool y
95ffa243
YL
1370 prompt "MTRR cleanup support"
1371 depends on MTRR
8f9ca475 1372 ---help---
aba3728c
TG
1373 Convert MTRR layout from continuous to discrete, so X drivers can
1374 add writeback entries.
95ffa243 1375
aba3728c 1376 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1377 The largest mtrr entry size for a continuous block can be set with
aba3728c 1378 mtrr_chunk_size.
95ffa243 1379
2ffb3501 1380 If unsure, say Y.
95ffa243
YL
1381
1382config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1383 int "MTRR cleanup enable value (0-1)"
1384 range 0 1
1385 default "0"
95ffa243 1386 depends on MTRR_SANITIZER
8f9ca475 1387 ---help---
f5098d62 1388 Enable mtrr cleanup default value
95ffa243 1389
12031a62
YL
1390config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1391 int "MTRR cleanup spare reg num (0-7)"
1392 range 0 7
1393 default "1"
1394 depends on MTRR_SANITIZER
8f9ca475 1395 ---help---
12031a62 1396 mtrr cleanup spare entries default, it can be changed via
aba3728c 1397 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1398
2e5d9c85 1399config X86_PAT
2a8a2719 1400 bool
2e5d9c85 1401 prompt "x86 PAT support"
2a8a2719 1402 depends on MTRR
8f9ca475 1403 ---help---
2e5d9c85 1404 Use PAT attributes to setup page level cache control.
042b78e4 1405
2e5d9c85 1406 PATs are the modern equivalents of MTRRs and are much more
1407 flexible than MTRRs.
1408
1409 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1410 spontaneous reboots) or a non-working video driver.
2e5d9c85 1411
1412 If unsure, say Y.
1413
506f1d07 1414config EFI
9ba16087 1415 bool "EFI runtime service support"
5b83683f 1416 depends on ACPI
506f1d07 1417 ---help---
8f9ca475
IM
1418 This enables the kernel to use EFI runtime services that are
1419 available (such as the EFI variable services).
506f1d07 1420
8f9ca475
IM
1421 This option is only useful on systems that have EFI firmware.
1422 In addition, you should use the latest ELILO loader available
1423 at <http://elilo.sourceforge.net> in order to take advantage
1424 of EFI runtime services. However, even with this option, the
1425 resultant kernel should continue to boot on existing non-EFI
1426 platforms.
506f1d07 1427
506f1d07 1428config SECCOMP
3c2362e6
HH
1429 def_bool y
1430 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1431 ---help---
506f1d07
SR
1432 This kernel feature is useful for number crunching applications
1433 that may need to compute untrusted bytecode during their
1434 execution. By using pipes or other transports made available to
1435 the process as file descriptors supporting the read/write
1436 syscalls, it's possible to isolate those applications in
1437 their own address space using seccomp. Once seccomp is
9c0bbee8 1438 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1439 and the task is only allowed to execute a few safe syscalls
1440 defined by each seccomp mode.
1441
1442 If unsure, say Y. Only embedded should say N here.
1443
113c5413
IM
1444config CC_STACKPROTECTOR_ALL
1445 bool
1446
506f1d07
SR
1447config CC_STACKPROTECTOR
1448 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
113c5413 1449 select CC_STACKPROTECTOR_ALL
8f9ca475
IM
1450 ---help---
1451 This option turns on the -fstack-protector GCC feature. This
113c5413
IM
1452 feature puts, at the beginning of functions, a canary value on
1453 the stack just before the return address, and validates
506f1d07
SR
1454 the value just before actually returning. Stack based buffer
1455 overflows (that need to overwrite this return address) now also
1456 overwrite the canary, which gets detected and the attack is then
1457 neutralized via a kernel panic.
1458
1459 This feature requires gcc version 4.2 or above, or a distribution
1460 gcc with the feature backported. Older versions are automatically
113c5413
IM
1461 detected and for those versions, this configuration option is
1462 ignored. (and a warning is printed during bootup)
506f1d07
SR
1463
1464source kernel/Kconfig.hz
1465
1466config KEXEC
1467 bool "kexec system call"
8f9ca475 1468 ---help---
506f1d07
SR
1469 kexec is a system call that implements the ability to shutdown your
1470 current kernel, and to start another kernel. It is like a reboot
1471 but it is independent of the system firmware. And like a reboot
1472 you can start any kernel with it, not just Linux.
1473
1474 The name comes from the similarity to the exec system call.
1475
1476 It is an ongoing process to be certain the hardware in a machine
1477 is properly shutdown, so do not be surprised if this code does not
1478 initially work for you. It may help to enable device hotplugging
1479 support. As of this writing the exact hardware interface is
1480 strongly in flux, so no good recommendation can be made.
1481
1482config CRASH_DUMP
04b69447 1483 bool "kernel crash dumps"
506f1d07 1484 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1485 ---help---
506f1d07
SR
1486 Generate crash dump after being started by kexec.
1487 This should be normally only set in special crash dump kernels
1488 which are loaded in the main kernel with kexec-tools into
1489 a specially reserved region and then later executed after
1490 a crash by kdump/kexec. The crash dump kernel must be compiled
1491 to a memory address not used by the main kernel or BIOS using
1492 PHYSICAL_START, or it must be built as a relocatable image
1493 (CONFIG_RELOCATABLE=y).
1494 For more details see Documentation/kdump/kdump.txt
1495
3ab83521
HY
1496config KEXEC_JUMP
1497 bool "kexec jump (EXPERIMENTAL)"
1498 depends on EXPERIMENTAL
fee7b0d8 1499 depends on KEXEC && HIBERNATION
8f9ca475 1500 ---help---
89081d17
HY
1501 Jump between original kernel and kexeced kernel and invoke
1502 code in physical address mode via KEXEC
3ab83521 1503
506f1d07
SR
1504config PHYSICAL_START
1505 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
ceefccc9 1506 default "0x1000000"
8f9ca475 1507 ---help---
506f1d07
SR
1508 This gives the physical address where the kernel is loaded.
1509
1510 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1511 bzImage will decompress itself to above physical address and
1512 run from there. Otherwise, bzImage will run from the address where
1513 it has been loaded by the boot loader and will ignore above physical
1514 address.
1515
1516 In normal kdump cases one does not have to set/change this option
1517 as now bzImage can be compiled as a completely relocatable image
1518 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1519 address. This option is mainly useful for the folks who don't want
1520 to use a bzImage for capturing the crash dump and want to use a
1521 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1522 to be specifically compiled to run from a specific memory area
1523 (normally a reserved region) and this option comes handy.
1524
ceefccc9
PA
1525 So if you are using bzImage for capturing the crash dump,
1526 leave the value here unchanged to 0x1000000 and set
1527 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1528 for capturing the crash dump change this value to start of
1529 the reserved region. In other words, it can be set based on
1530 the "X" value as specified in the "crashkernel=YM@XM"
1531 command line boot parameter passed to the panic-ed
1532 kernel. Please take a look at Documentation/kdump/kdump.txt
1533 for more details about crash dumps.
506f1d07
SR
1534
1535 Usage of bzImage for capturing the crash dump is recommended as
1536 one does not have to build two kernels. Same kernel can be used
1537 as production kernel and capture kernel. Above option should have
1538 gone away after relocatable bzImage support is introduced. But it
1539 is present because there are users out there who continue to use
1540 vmlinux for dump capture. This option should go away down the
1541 line.
1542
1543 Don't change this unless you know what you are doing.
1544
1545config RELOCATABLE
26717808
PA
1546 bool "Build a relocatable kernel"
1547 default y
8f9ca475 1548 ---help---
506f1d07
SR
1549 This builds a kernel image that retains relocation information
1550 so it can be loaded someplace besides the default 1MB.
1551 The relocations tend to make the kernel binary about 10% larger,
1552 but are discarded at runtime.
1553
1554 One use is for the kexec on panic case where the recovery kernel
1555 must live at a different physical address than the primary
1556 kernel.
1557
1558 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1559 it has been loaded at and the compile time physical address
1560 (CONFIG_PHYSICAL_START) is ignored.
1561
845adf72
PA
1562# Relocation on x86-32 needs some additional build support
1563config X86_NEED_RELOCS
1564 def_bool y
1565 depends on X86_32 && RELOCATABLE
1566
506f1d07
SR
1567config PHYSICAL_ALIGN
1568 hex
1569 prompt "Alignment value to which kernel should be aligned" if X86_32
ceefccc9
PA
1570 default "0x1000000"
1571 range 0x2000 0x1000000
8f9ca475 1572 ---help---
506f1d07
SR
1573 This value puts the alignment restrictions on physical address
1574 where kernel is loaded and run from. Kernel is compiled for an
1575 address which meets above alignment restriction.
1576
1577 If bootloader loads the kernel at a non-aligned address and
1578 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1579 address aligned to above value and run from there.
1580
1581 If bootloader loads the kernel at a non-aligned address and
1582 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1583 load address and decompress itself to the address it has been
1584 compiled for and run from there. The address for which kernel is
1585 compiled already meets above alignment restrictions. Hence the
1586 end result is that kernel runs from a physical address meeting
1587 above alignment restrictions.
1588
1589 Don't change this unless you know what you are doing.
1590
1591config HOTPLUG_CPU
7c13e6a3 1592 bool "Support for hot-pluggable CPUs"
4b19ed91 1593 depends on SMP && HOTPLUG
506f1d07 1594 ---help---
7c13e6a3
DS
1595 Say Y here to allow turning CPUs off and on. CPUs can be
1596 controlled through /sys/devices/system/cpu.
1597 ( Note: power management support will enable this option
1598 automatically on SMP systems. )
1599 Say N if you want to disable CPU hotplug.
506f1d07
SR
1600
1601config COMPAT_VDSO
3c2362e6
HH
1602 def_bool y
1603 prompt "Compat VDSO support"
af65d648 1604 depends on X86_32 || IA32_EMULATION
8f9ca475 1605 ---help---
af65d648 1606 Map the 32-bit VDSO to the predictable old-style address too.
506f1d07
SR
1607 ---help---
1608 Say N here if you are running a sufficiently recent glibc
1609 version (2.3.3 or later), to remove the high-mapped
1610 VDSO mapping and to exclusively use the randomized VDSO.
1611
1612 If unsure, say Y.
1613
516cbf37
TB
1614config CMDLINE_BOOL
1615 bool "Built-in kernel command line"
1616 default n
8f9ca475 1617 ---help---
516cbf37
TB
1618 Allow for specifying boot arguments to the kernel at
1619 build time. On some systems (e.g. embedded ones), it is
1620 necessary or convenient to provide some or all of the
1621 kernel boot arguments with the kernel itself (that is,
1622 to not rely on the boot loader to provide them.)
1623
1624 To compile command line arguments into the kernel,
1625 set this option to 'Y', then fill in the
1626 the boot arguments in CONFIG_CMDLINE.
1627
1628 Systems with fully functional boot loaders (i.e. non-embedded)
1629 should leave this option set to 'N'.
1630
1631config CMDLINE
1632 string "Built-in kernel command string"
1633 depends on CMDLINE_BOOL
1634 default ""
8f9ca475 1635 ---help---
516cbf37
TB
1636 Enter arguments here that should be compiled into the kernel
1637 image and used at boot time. If the boot loader provides a
1638 command line at boot time, it is appended to this string to
1639 form the full kernel command line, when the system boots.
1640
1641 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1642 change this behavior.
1643
1644 In most cases, the command line (whether built-in or provided
1645 by the boot loader) should specify the device for the root
1646 file system.
1647
1648config CMDLINE_OVERRIDE
1649 bool "Built-in command line overrides boot loader arguments"
1650 default n
1651 depends on CMDLINE_BOOL
8f9ca475 1652 ---help---
516cbf37
TB
1653 Set this option to 'Y' to have the kernel ignore the boot loader
1654 command line, and use ONLY the built-in command line.
1655
1656 This is used to work around broken boot loaders. This should
1657 be set to 'N' under normal conditions.
1658
506f1d07
SR
1659endmenu
1660
1661config ARCH_ENABLE_MEMORY_HOTPLUG
1662 def_bool y
1663 depends on X86_64 || (X86_32 && HIGHMEM)
1664
35551053
GH
1665config ARCH_ENABLE_MEMORY_HOTREMOVE
1666 def_bool y
1667 depends on MEMORY_HOTPLUG
1668
506f1d07
SR
1669config HAVE_ARCH_EARLY_PFN_TO_NID
1670 def_bool X86_64
1671 depends on NUMA
1672
da85f865 1673menu "Power management and ACPI options"
e279b6c1
SR
1674
1675config ARCH_HIBERNATION_HEADER
3c2362e6 1676 def_bool y
e279b6c1 1677 depends on X86_64 && HIBERNATION
e279b6c1
SR
1678
1679source "kernel/power/Kconfig"
1680
1681source "drivers/acpi/Kconfig"
1682
a6b68076
AK
1683config X86_APM_BOOT
1684 bool
1685 default y
1686 depends on APM || APM_MODULE
1687
e279b6c1
SR
1688menuconfig APM
1689 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 1690 depends on X86_32 && PM_SLEEP
e279b6c1
SR
1691 ---help---
1692 APM is a BIOS specification for saving power using several different
1693 techniques. This is mostly useful for battery powered laptops with
1694 APM compliant BIOSes. If you say Y here, the system time will be
1695 reset after a RESUME operation, the /proc/apm device will provide
1696 battery status information, and user-space programs will receive
1697 notification of APM "events" (e.g. battery status change).
1698
1699 If you select "Y" here, you can disable actual use of the APM
1700 BIOS by passing the "apm=off" option to the kernel at boot time.
1701
1702 Note that the APM support is almost completely disabled for
1703 machines with more than one CPU.
1704
1705 In order to use APM, you will need supporting software. For location
53471121 1706 and more information, read <file:Documentation/power/pm.txt> and the
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1707 Battery Powered Linux mini-HOWTO, available from
1708 <http://www.tldp.org/docs.html#howto>.
1709
1710 This driver does not spin down disk drives (see the hdparm(8)
1711 manpage ("man 8 hdparm") for that), and it doesn't turn off
1712 VESA-compliant "green" monitors.
1713
1714 This driver does not support the TI 4000M TravelMate and the ACER
1715 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1716 desktop machines also don't have compliant BIOSes, and this driver
1717 may cause those machines to panic during the boot phase.
1718
1719 Generally, if you don't have a battery in your machine, there isn't
1720 much point in using this driver and you should say N. If you get
1721 random kernel OOPSes or reboots that don't seem to be related to
1722 anything, try disabling/enabling this option (or disabling/enabling
1723 APM in your BIOS).
1724
1725 Some other things you should try when experiencing seemingly random,
1726 "weird" problems:
1727
1728 1) make sure that you have enough swap space and that it is
1729 enabled.
1730 2) pass the "no-hlt" option to the kernel
1731 3) switch on floating point emulation in the kernel and pass
1732 the "no387" option to the kernel
1733 4) pass the "floppy=nodma" option to the kernel
1734 5) pass the "mem=4M" option to the kernel (thereby disabling
1735 all but the first 4 MB of RAM)
1736 6) make sure that the CPU is not over clocked.
1737 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1738 8) disable the cache from your BIOS settings
1739 9) install a fan for the video card or exchange video RAM
1740 10) install a better fan for the CPU
1741 11) exchange RAM chips
1742 12) exchange the motherboard.
1743
1744 To compile this driver as a module, choose M here: the
1745 module will be called apm.
1746
1747if APM
1748
1749config APM_IGNORE_USER_SUSPEND
1750 bool "Ignore USER SUSPEND"
8f9ca475 1751 ---help---
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1752 This option will ignore USER SUSPEND requests. On machines with a
1753 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1754 series notebooks, it is necessary to say Y because of a BIOS bug.
1755
1756config APM_DO_ENABLE
1757 bool "Enable PM at boot time"
1758 ---help---
1759 Enable APM features at boot time. From page 36 of the APM BIOS
1760 specification: "When disabled, the APM BIOS does not automatically
1761 power manage devices, enter the Standby State, enter the Suspend
1762 State, or take power saving steps in response to CPU Idle calls."
1763 This driver will make CPU Idle calls when Linux is idle (unless this
1764 feature is turned off -- see "Do CPU IDLE calls", below). This
1765 should always save battery power, but more complicated APM features
1766 will be dependent on your BIOS implementation. You may need to turn
1767 this option off if your computer hangs at boot time when using APM
1768 support, or if it beeps continuously instead of suspending. Turn
1769 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1770 T400CDT. This is off by default since most machines do fine without
1771 this feature.
1772
1773config APM_CPU_IDLE
1774 bool "Make CPU Idle calls when idle"
8f9ca475 1775 ---help---
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1776 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1777 On some machines, this can activate improved power savings, such as
1778 a slowed CPU clock rate, when the machine is idle. These idle calls
1779 are made after the idle loop has run for some length of time (e.g.,
1780 333 mS). On some machines, this will cause a hang at boot time or
1781 whenever the CPU becomes idle. (On machines with more than one CPU,
1782 this option does nothing.)
1783
1784config APM_DISPLAY_BLANK
1785 bool "Enable console blanking using APM"
8f9ca475 1786 ---help---
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1787 Enable console blanking using the APM. Some laptops can use this to
1788 turn off the LCD backlight when the screen blanker of the Linux
1789 virtual console blanks the screen. Note that this is only used by
1790 the virtual console screen blanker, and won't turn off the backlight
1791 when using the X Window system. This also doesn't have anything to
1792 do with your VESA-compliant power-saving monitor. Further, this
1793 option doesn't work for all laptops -- it might not turn off your
1794 backlight at all, or it might print a lot of errors to the console,
1795 especially if you are using gpm.
1796
1797config APM_ALLOW_INTS
1798 bool "Allow interrupts during APM BIOS calls"
8f9ca475 1799 ---help---
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1800 Normally we disable external interrupts while we are making calls to
1801 the APM BIOS as a measure to lessen the effects of a badly behaving
1802 BIOS implementation. The BIOS should reenable interrupts if it
1803 needs to. Unfortunately, some BIOSes do not -- especially those in
1804 many of the newer IBM Thinkpads. If you experience hangs when you
1805 suspend, try setting this to Y. Otherwise, say N.
1806
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1807endif # APM
1808
1809source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1810
1811source "drivers/cpuidle/Kconfig"
1812
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1813source "drivers/idle/Kconfig"
1814
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1815endmenu
1816
1817
1818menu "Bus options (PCI etc.)"
1819
1820config PCI
1ac97018 1821 bool "PCI support"
1c858087 1822 default y
e279b6c1 1823 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
8f9ca475 1824 ---help---
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1825 Find out whether you have a PCI motherboard. PCI is the name of a
1826 bus system, i.e. the way the CPU talks to the other stuff inside
1827 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1828 VESA. If you have PCI, say Y, otherwise N.
1829
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1830choice
1831 prompt "PCI access mode"
efefa6f6 1832 depends on X86_32 && PCI
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1833 default PCI_GOANY
1834 ---help---
1835 On PCI systems, the BIOS can be used to detect the PCI devices and
1836 determine their configuration. However, some old PCI motherboards
1837 have BIOS bugs and may crash if this is done. Also, some embedded
1838 PCI-based systems don't have any BIOS at all. Linux can also try to
1839 detect the PCI hardware directly without using the BIOS.
1840
1841 With this option, you can specify how Linux should detect the
1842 PCI devices. If you choose "BIOS", the BIOS will be used,
1843 if you choose "Direct", the BIOS won't be used, and if you
1844 choose "MMConfig", then PCI Express MMCONFIG will be used.
1845 If you choose "Any", the kernel will try MMCONFIG, then the
1846 direct access method and falls back to the BIOS if that doesn't
1847 work. If unsure, go with the default, which is "Any".
1848
1849config PCI_GOBIOS
1850 bool "BIOS"
1851
1852config PCI_GOMMCONFIG
1853 bool "MMConfig"
1854
1855config PCI_GODIRECT
1856 bool "Direct"
1857
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1858config PCI_GOOLPC
1859 bool "OLPC"
1860 depends on OLPC
1861
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1862config PCI_GOANY
1863 bool "Any"
1864
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1865endchoice
1866
1867config PCI_BIOS
3c2362e6 1868 def_bool y
efefa6f6 1869 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
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1870
1871# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1872config PCI_DIRECT
3c2362e6 1873 def_bool y
efefa6f6 1874 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
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1875
1876config PCI_MMCONFIG
3c2362e6 1877 def_bool y
e279b6c1 1878 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 1879
3ef0e1f8 1880config PCI_OLPC
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1881 def_bool y
1882 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 1883
e279b6c1 1884config PCI_DOMAINS
3c2362e6 1885 def_bool y
e279b6c1 1886 depends on PCI
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1887
1888config PCI_MMCONFIG
1889 bool "Support mmconfig PCI config space access"
1890 depends on X86_64 && PCI && ACPI
1891
1892config DMAR
1893 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
4cf2e75d 1894 depends on PCI_MSI && ACPI && EXPERIMENTAL
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1895 help
1896 DMA remapping (DMAR) devices support enables independent address
1897 translations for Direct Memory Access (DMA) from devices.
1898 These DMA remapping devices are reported via ACPI tables
1899 and include PCI device scope covered by these DMA
1900 remapping devices.
1901
0cd5c3c8 1902config DMAR_DEFAULT_ON
f6be37fd 1903 def_bool y
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KM
1904 prompt "Enable DMA Remapping Devices by default"
1905 depends on DMAR
1906 help
1907 Selecting this option will enable a DMAR device at boot time if
1908 one is found. If this option is not selected, DMAR support can
1909 be enabled by passing intel_iommu=on to the kernel. It is
1910 recommended you say N here while the DMAR code remains
1911 experimental.
1912
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1913config DMAR_BROKEN_GFX_WA
1914 def_bool n
1915 prompt "Workaround broken graphics drivers (going away soon)"
1916 depends on DMAR
1917 ---help---
1918 Current Graphics drivers tend to use physical address
1919 for DMA and avoid using DMA APIs. Setting this config
1920 option permits the IOMMU driver to set a unity map for
1921 all the OS-visible memory. Hence the driver can continue
1922 to use physical addresses for DMA, at least until this
1923 option is removed in the 2.6.32 kernel.
1924
e279b6c1 1925config DMAR_FLOPPY_WA
3c2362e6 1926 def_bool y
e279b6c1 1927 depends on DMAR
8f9ca475 1928 ---help---
c7ab48d2 1929 Floppy disk drivers are known to bypass DMA API calls
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1930 thereby failing to work when IOMMU is enabled. This
1931 workaround will setup a 1:1 mapping for the first
c7ab48d2 1932 16MiB to make floppy (an ISA device) work.
e279b6c1 1933
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SS
1934config INTR_REMAP
1935 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1936 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
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IM
1937 ---help---
1938 Supports Interrupt remapping for IO-APIC and MSI devices.
1939 To use x2apic mode in the CPU's which support x2APIC enhancements or
1940 to support platforms with CPU's having > 8 bit APIC ID, say Y.
9fa8c481 1941
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1942source "drivers/pci/pcie/Kconfig"
1943
1944source "drivers/pci/Kconfig"
1945
1946# x86_64 have no ISA slots, but do have ISA-style DMA.
1947config ISA_DMA_API
3c2362e6 1948 def_bool y
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1949
1950if X86_32
1951
1952config ISA
1953 bool "ISA support"
8f9ca475 1954 ---help---
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1955 Find out whether you have ISA slots on your motherboard. ISA is the
1956 name of a bus system, i.e. the way the CPU talks to the other stuff
1957 inside your box. Other bus systems are PCI, EISA, MicroChannel
1958 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1959 newer boards don't support it. If you have ISA, say Y, otherwise N.
1960
1961config EISA
1962 bool "EISA support"
1963 depends on ISA
1964 ---help---
1965 The Extended Industry Standard Architecture (EISA) bus was
1966 developed as an open alternative to the IBM MicroChannel bus.
1967
1968 The EISA bus provided some of the features of the IBM MicroChannel
1969 bus while maintaining backward compatibility with cards made for
1970 the older ISA bus. The EISA bus saw limited use between 1988 and
1971 1995 when it was made obsolete by the PCI bus.
1972
1973 Say Y here if you are building a kernel for an EISA-based machine.
1974
1975 Otherwise, say N.
1976
1977source "drivers/eisa/Kconfig"
1978
1979config MCA
72ee6ebb 1980 bool "MCA support"
8f9ca475 1981 ---help---
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1982 MicroChannel Architecture is found in some IBM PS/2 machines and
1983 laptops. It is a bus system similar to PCI or ISA. See
1984 <file:Documentation/mca.txt> (and especially the web page given
1985 there) before attempting to build an MCA bus kernel.
1986
1987source "drivers/mca/Kconfig"
1988
1989config SCx200
1990 tristate "NatSemi SCx200 support"
8f9ca475 1991 ---help---
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1992 This provides basic support for National Semiconductor's
1993 (now AMD's) Geode processors. The driver probes for the
1994 PCI-IDs of several on-chip devices, so its a good dependency
1995 for other scx200_* drivers.
1996
1997 If compiled as a module, the driver is named scx200.
1998
1999config SCx200HR_TIMER
2000 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2001 depends on SCx200 && GENERIC_TIME
2002 default y
8f9ca475 2003 ---help---
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SR
2004 This driver provides a clocksource built upon the on-chip
2005 27MHz high-resolution timer. Its also a workaround for
2006 NSC Geode SC-1100's buggy TSC, which loses time when the
2007 processor goes idle (as is done by the scheduler). The
2008 other workaround is idle=poll boot option.
2009
2010config GEODE_MFGPT_TIMER
3c2362e6
HH
2011 def_bool y
2012 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
e279b6c1 2013 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
8f9ca475 2014 ---help---
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2015 This driver provides a clock event source based on the MFGPT
2016 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2017 MFGPTs have a better resolution and max interval than the
2018 generic PIT, and are suitable for use as high-res timers.
2019
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2020config OLPC
2021 bool "One Laptop Per Child support"
2022 default n
8f9ca475 2023 ---help---
3ef0e1f8
AS
2024 Add support for detecting the unique features of the OLPC
2025 XO hardware.
2026
bc0120fd
SR
2027endif # X86_32
2028
e279b6c1
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2029config K8_NB
2030 def_bool y
bc0120fd 2031 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
e279b6c1
SR
2032
2033source "drivers/pcmcia/Kconfig"
2034
2035source "drivers/pci/hotplug/Kconfig"
2036
2037endmenu
2038
2039
2040menu "Executable file formats / Emulations"
2041
2042source "fs/Kconfig.binfmt"
2043
2044config IA32_EMULATION
2045 bool "IA32 Emulation"
2046 depends on X86_64
a97f52e6 2047 select COMPAT_BINFMT_ELF
8f9ca475 2048 ---help---
e279b6c1
SR
2049 Include code to run 32-bit programs under a 64-bit kernel. You should
2050 likely turn this on, unless you're 100% sure that you don't have any
2051 32-bit programs left.
2052
2053config IA32_AOUT
8f9ca475
IM
2054 tristate "IA32 a.out support"
2055 depends on IA32_EMULATION
2056 ---help---
2057 Support old a.out binaries in the 32bit emulation.
e279b6c1
SR
2058
2059config COMPAT
3c2362e6 2060 def_bool y
e279b6c1 2061 depends on IA32_EMULATION
e279b6c1
SR
2062
2063config COMPAT_FOR_U64_ALIGNMENT
2064 def_bool COMPAT
2065 depends on X86_64
2066
2067config SYSVIPC_COMPAT
3c2362e6 2068 def_bool y
b8992195 2069 depends on COMPAT && SYSVIPC
e279b6c1
SR
2070
2071endmenu
2072
2073
e5beae16
KP
2074config HAVE_ATOMIC_IOMAP
2075 def_bool y
2076 depends on X86_32
2077
e279b6c1
SR
2078source "net/Kconfig"
2079
2080source "drivers/Kconfig"
2081
2082source "drivers/firmware/Kconfig"
2083
2084source "fs/Kconfig"
2085
e279b6c1
SR
2086source "arch/x86/Kconfig.debug"
2087
2088source "security/Kconfig"
2089
2090source "crypto/Kconfig"
2091
edf88417
AK
2092source "arch/x86/kvm/Kconfig"
2093
e279b6c1 2094source "lib/Kconfig"