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1032c0ba 1# x86 configuration
daa93fab
SR
2mainmenu "Linux Kernel Configuration for x86"
3
4# Select 32 or 64 bit
5config 64BIT
6840999b
SR
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
8f9ca475 8 ---help---
daa93fab
SR
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
1032c0ba
SR
17
18### Arch settings
8d5fffb9 19config X86
3c2362e6 20 def_bool y
e17c6d56 21 select HAVE_AOUT if X86_32
2c5643b1
HM
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
cdd6c482 27 select HAVE_PERF_EVENTS if (!M386 && !M486)
e360adbe 28 select HAVE_IRQ_WORK
28b2ee20 29 select HAVE_IOREMAP_PROT
3f550096 30 select HAVE_KPROBES
1f972768 31 select ARCH_WANT_OPTIONAL_GPIOLIB
da4276b8 32 select ARCH_WANT_FRAME_POINTERS
7c095e46 33 select HAVE_DMA_ATTRS
9edddaa2 34 select HAVE_KRETPROBES
c0f7ac3a 35 select HAVE_OPTPROBES
e4b2b886 36 select HAVE_FTRACE_MCOUNT_RECORD
cf4db259 37 select HAVE_C_RECORDMCOUNT
677aa9f7 38 select HAVE_DYNAMIC_FTRACE
606576ce 39 select HAVE_FUNCTION_TRACER
48d68b20 40 select HAVE_FUNCTION_GRAPH_TRACER
71e308a2 41 select HAVE_FUNCTION_GRAPH_FP_TEST
60a7ecf4 42 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
9a5fd902 43 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
66700001 44 select HAVE_SYSCALL_TRACEPOINTS
e0ec9483 45 select HAVE_KVM
49793b03 46 select HAVE_ARCH_KGDB
99bbc4b1 47 select HAVE_ARCH_TRACEHOOK
323ec001 48 select HAVE_GENERIC_DMA_COHERENT if X86_32
58340a07 49 select HAVE_EFFICIENT_UNALIGNED_ACCESS
8d26487f 50 select USER_STACKTRACE_SUPPORT
f850c30c 51 select HAVE_REGS_AND_STACK_ACCESS_API
2118d0c5 52 select HAVE_DMA_API_DEBUG
2e9f3bdd
PA
53 select HAVE_KERNEL_GZIP
54 select HAVE_KERNEL_BZIP2
55 select HAVE_KERNEL_LZMA
13510997 56 select HAVE_KERNEL_LZO
0067f129 57 select HAVE_HW_BREAKPOINT
0102752e 58 select HAVE_MIXED_BREAKPOINTS_REGS
99e8c5a3 59 select PERF_EVENTS
c01d4323 60 select HAVE_PERF_EVENTS_NMI
99e8c5a3 61 select ANON_INODES
0a4af3b0 62 select HAVE_ARCH_KMEMCHECK
7c68af6e 63 select HAVE_USER_RETURN_NOTIFIER
46eb3b64 64 select HAVE_ARCH_JUMP_LABEL
3cba11d3 65 select HAVE_TEXT_POKE_SMP
7d8330a5 66
ba7e4d13
IM
67config INSTRUCTION_DECODER
68 def_bool (KPROBES || PERF_EVENTS)
69
51b26ada
LT
70config OUTPUT_FORMAT
71 string
72 default "elf32-i386" if X86_32
73 default "elf64-x86-64" if X86_64
74
73531905 75config ARCH_DEFCONFIG
b9b39bfb 76 string
73531905
SR
77 default "arch/x86/configs/i386_defconfig" if X86_32
78 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 79
8d5fffb9 80config GENERIC_CMOS_UPDATE
3c2362e6 81 def_bool y
8d5fffb9
SR
82
83config CLOCKSOURCE_WATCHDOG
3c2362e6 84 def_bool y
8d5fffb9
SR
85
86config GENERIC_CLOCKEVENTS
3c2362e6 87 def_bool y
8d5fffb9
SR
88
89config GENERIC_CLOCKEVENTS_BROADCAST
3c2362e6 90 def_bool y
8d5fffb9
SR
91 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
92
93config LOCKDEP_SUPPORT
3c2362e6 94 def_bool y
8d5fffb9
SR
95
96config STACKTRACE_SUPPORT
3c2362e6 97 def_bool y
8d5fffb9 98
aa7d9350
HC
99config HAVE_LATENCYTOP_SUPPORT
100 def_bool y
101
8d5fffb9 102config MMU
3c2362e6 103 def_bool y
8d5fffb9
SR
104
105config ZONE_DMA
3c2362e6 106 def_bool y
8d5fffb9 107
8d5fffb9
SR
108config SBUS
109 bool
110
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FT
111config NEED_DMA_MAP_STATE
112 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
113
18e98307 114config NEED_SG_DMA_LENGTH
4a14d84e 115 def_bool y
18e98307 116
8d5fffb9 117config GENERIC_ISA_DMA
3c2362e6 118 def_bool y
8d5fffb9
SR
119
120config GENERIC_IOMAP
3c2362e6 121 def_bool y
8d5fffb9
SR
122
123config GENERIC_BUG
3c2362e6 124 def_bool y
8d5fffb9 125 depends on BUG
b93a531e
JB
126 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
127
128config GENERIC_BUG_RELATIVE_POINTERS
129 bool
8d5fffb9
SR
130
131config GENERIC_HWEIGHT
3c2362e6 132 def_bool y
8d5fffb9 133
a6082959 134config GENERIC_GPIO
9ba16087 135 bool
a6082959 136
8d5fffb9 137config ARCH_MAY_HAVE_PC_FDC
3c2362e6 138 def_bool y
8d5fffb9 139
1032c0ba
SR
140config RWSEM_GENERIC_SPINLOCK
141 def_bool !X86_XADD
142
143config RWSEM_XCHGADD_ALGORITHM
144 def_bool X86_XADD
145
a6869cc4
VP
146config ARCH_HAS_CPU_IDLE_WAIT
147 def_bool y
148
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SR
149config GENERIC_CALIBRATE_DELAY
150 def_bool y
151
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SR
152config GENERIC_TIME_VSYSCALL
153 bool
154 default X86_64
155
9a0b8415 156config ARCH_HAS_CPU_RELAX
157 def_bool y
158
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VP
159config ARCH_HAS_DEFAULT_IDLE
160 def_bool y
161
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PE
162config ARCH_HAS_CACHE_LINE_SIZE
163 def_bool y
164
dd5af90a 165config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 166 def_bool y
b32ef636 167
08fc4580
TH
168config NEED_PER_CPU_EMBED_FIRST_CHUNK
169 def_bool y
170
171config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
172 def_bool y
173
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MT
174config HAVE_CPUMASK_OF_CPU_MAP
175 def_bool X86_64_SMP
176
801e4062
JB
177config ARCH_HIBERNATION_POSSIBLE
178 def_bool y
801e4062 179
f4cb5700
JB
180config ARCH_SUSPEND_POSSIBLE
181 def_bool y
f4cb5700 182
8d5fffb9
SR
183config ZONE_DMA32
184 bool
185 default X86_64
186
187config ARCH_POPULATES_NODE_MAP
188 def_bool y
189
190config AUDIT_ARCH
191 bool
192 default X86_64
193
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IM
194config ARCH_SUPPORTS_OPTIMIZED_INLINING
195 def_bool y
196
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AM
197config ARCH_SUPPORTS_DEBUG_PAGEALLOC
198 def_bool y
199
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YL
200config HAVE_EARLY_RES
201 def_bool y
202
69575d38
SW
203config HAVE_INTEL_TXT
204 def_bool y
205 depends on EXPERIMENTAL && DMAR && ACPI
206
8d5fffb9
SR
207# Use the generic interrupt handling code in kernel/irq/:
208config GENERIC_HARDIRQS
6fc108a0 209 def_bool y
8d5fffb9 210
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TG
211config GENERIC_HARDIRQS_NO__DO_IRQ
212 def_bool y
213
8d5fffb9 214config GENERIC_IRQ_PROBE
6fc108a0 215 def_bool y
8d5fffb9
SR
216
217config GENERIC_PENDING_IRQ
6fc108a0 218 def_bool y
8d5fffb9 219 depends on GENERIC_HARDIRQS && SMP
8d5fffb9 220
6cd10f8d
JB
221config USE_GENERIC_SMP_HELPERS
222 def_bool y
223 depends on SMP
224
6b0c3d44
SR
225config X86_32_SMP
226 def_bool y
227 depends on X86_32 && SMP
228
229config X86_64_SMP
230 def_bool y
231 depends on X86_64 && SMP
232
8d5fffb9 233config X86_HT
6fc108a0 234 def_bool y
ee0011a7 235 depends on SMP
8d5fffb9
SR
236
237config X86_TRAMPOLINE
6fc108a0 238 def_bool y
3e5095d1 239 depends on SMP || (64BIT && ACPI_SLEEP)
8d5fffb9 240
ccbeed3a
TH
241config X86_32_LAZY_GS
242 def_bool y
60a5317f 243 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 244
d61931d8
BP
245config ARCH_HWEIGHT_CFLAGS
246 string
247 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
248 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
249
8d5fffb9
SR
250config KTIME_SCALAR
251 def_bool X86_32
d7c53c9e
BP
252
253config ARCH_CPU_PROBE_RELEASE
254 def_bool y
255 depends on HOTPLUG_CPU
256
506f1d07 257source "init/Kconfig"
dc52ddc0 258source "kernel/Kconfig.freezer"
8d5fffb9 259
506f1d07
SR
260menu "Processor type and features"
261
262source "kernel/time/Kconfig"
263
264config SMP
265 bool "Symmetric multi-processing support"
266 ---help---
267 This enables support for systems with more than one CPU. If you have
268 a system with only one CPU, like most personal computers, say N. If
269 you have a system with more than one CPU, say Y.
270
271 If you say N here, the kernel will run on single and multiprocessor
272 machines, but will use only one CPU of a multiprocessor machine. If
273 you say Y here, the kernel will run on many, but not all,
274 singleprocessor machines. On a singleprocessor machine, the kernel
275 will run faster if you say N here.
276
277 Note that if you say Y here and choose architecture "586" or
278 "Pentium" under "Processor family", the kernel will not work on 486
279 architectures. Similarly, multiprocessor kernels for the "PPro"
280 architecture may not work on all Pentium based boards.
281
282 People using multiprocessor machines who say Y here should also say
283 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
284 Management" code will be disabled if you say Y here.
285
03502faa 286 See also <file:Documentation/i386/IO-APIC.txt>,
506f1d07
SR
287 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
288 <http://www.tldp.org/docs.html#howto>.
289
290 If you don't know what to do here, say N.
291
06cd9a7d
YL
292config X86_X2APIC
293 bool "Support x2apic"
f7d7f866 294 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
06cd9a7d
YL
295 ---help---
296 This enables x2apic support on CPUs that have this feature.
297
298 This allows 32-bit apic IDs (so it can support very large systems),
299 and accesses the local apic via MSRs not via mmio.
300
06cd9a7d
YL
301 If you don't know what to do here, say N.
302
0b8f1efa
YL
303config SPARSE_IRQ
304 bool "Support sparse irq numbering"
17483a1f 305 depends on PCI_MSI || HT_IRQ
8f9ca475 306 ---help---
973656fe
IM
307 This enables support for sparse irqs. This is useful for distro
308 kernels that want to define a high CONFIG_NR_CPUS value but still
309 want to have low kernel memory footprint on smaller machines.
0b8f1efa 310
973656fe
IM
311 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
312 out the irq_desc[] array in a more NUMA-friendly way. )
313
314 If you don't know what to do here, say N.
0b8f1efa 315
15e957d0
YL
316config NUMA_IRQ_DESC
317 def_bool y
b9098957 318 depends on SPARSE_IRQ && NUMA
48a1b10a 319
6695c85b 320config X86_MPPARSE
7a527688
JB
321 bool "Enable MPS table" if ACPI
322 default y
5ab74722 323 depends on X86_LOCAL_APIC
8f9ca475 324 ---help---
6695c85b
YL
325 For old smp systems that do not have proper acpi support. Newer systems
326 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 327
26f7ef14
YL
328config X86_BIGSMP
329 bool "Support for big SMP systems with more than 8 CPUs"
330 depends on X86_32 && SMP
8f9ca475 331 ---help---
26f7ef14 332 This option is needed for the systems that have more than 8 CPUs
506f1d07 333
8425091f 334if X86_32
c5c606d9
RT
335config X86_EXTENDED_PLATFORM
336 bool "Support for extended (non-PC) x86 platforms"
337 default y
8f9ca475 338 ---help---
06ac8346
IM
339 If you disable this option then the kernel will only support
340 standard PC platforms. (which covers the vast majority of
341 systems out there.)
342
8425091f
RT
343 If you enable this option then you'll be able to select support
344 for the following (non-PC) 32 bit x86 platforms:
345 AMD Elan
346 NUMAQ (IBM/Sequent)
347 RDC R-321x SoC
348 SGI 320/540 (Visual Workstation)
349 Summit/EXA (IBM x440)
350 Unisys ES7000 IA32 series
3f4110a4 351 Moorestown MID devices
06ac8346
IM
352
353 If you have one of these systems, or if you want to build a
354 generic distribution kernel, say Y here - otherwise say N.
8425091f 355endif
06ac8346 356
8425091f
RT
357if X86_64
358config X86_EXTENDED_PLATFORM
359 bool "Support for extended (non-PC) x86 platforms"
360 default y
361 ---help---
362 If you disable this option then the kernel will only support
363 standard PC platforms. (which covers the vast majority of
364 systems out there.)
365
366 If you enable this option then you'll be able to select support
367 for the following (non-PC) 64 bit x86 platforms:
368 ScaleMP vSMP
369 SGI Ultraviolet
370
371 If you have one of these systems, or if you want to build a
372 generic distribution kernel, say Y here - otherwise say N.
373endif
c5c606d9
RT
374# This is an alphabetically sorted list of 64 bit extended platforms
375# Please maintain the alphabetic order if and when there are additions
506f1d07 376
c5c606d9
RT
377config X86_VSMP
378 bool "ScaleMP vSMP"
379 select PARAVIRT
380 depends on X86_64 && PCI
381 depends on X86_EXTENDED_PLATFORM
8f9ca475 382 ---help---
c5c606d9
RT
383 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
384 supposed to run on these EM64T-based machines. Only choose this option
385 if you have one of these machines.
5e3a77e9 386
03b48632
NP
387config X86_UV
388 bool "SGI Ultraviolet"
389 depends on X86_64
c5c606d9 390 depends on X86_EXTENDED_PLATFORM
54c28d29 391 depends on NUMA
9d6c26e7 392 depends on X86_X2APIC
8f9ca475 393 ---help---
03b48632
NP
394 This option is needed in order to support SGI Ultraviolet systems.
395 If you don't have one of these, you should say N here.
396
c5c606d9
RT
397# Following is an alphabetically sorted list of 32 bit extended platforms
398# Please maintain the alphabetic order if and when there are additions
506f1d07
SR
399
400config X86_ELAN
401 bool "AMD Elan"
402 depends on X86_32
c5c606d9 403 depends on X86_EXTENDED_PLATFORM
8f9ca475 404 ---help---
506f1d07
SR
405 Select this for an AMD Elan processor.
406
407 Do not use this option for K6/Athlon/Opteron processors!
408
409 If unsure, choose "PC-compatible" instead.
410
3f4110a4
TG
411config X86_MRST
412 bool "Moorestown MID platform"
4b2f3f7d
JP
413 depends on PCI
414 depends on PCI_GOANY
3f4110a4
TG
415 depends on X86_32
416 depends on X86_EXTENDED_PLATFORM
4b2f3f7d 417 depends on X86_IO_APIC
bb24c471 418 select APB_TIMER
3f4110a4
TG
419 ---help---
420 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
421 Internet Device(MID) platform. Moorestown consists of two chips:
422 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
423 Unlike standard x86 PCs, Moorestown does not have many legacy devices
424 nor standard legacy replacement devices/features. e.g. Moorestown does
425 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
426
c5c606d9
RT
427config X86_RDC321X
428 bool "RDC R-321x SoC"
506f1d07 429 depends on X86_32
c5c606d9
RT
430 depends on X86_EXTENDED_PLATFORM
431 select M486
432 select X86_REBOOTFIXUPS
433 ---help---
434 This option is needed for RDC R-321x system-on-chip, also known
435 as R-8610-(G).
436 If you don't have one of these chips, you should say N here.
437
e0c7ae37 438config X86_32_NON_STANDARD
9c398017
IM
439 bool "Support non-standard 32-bit SMP architectures"
440 depends on X86_32 && SMP
c5c606d9 441 depends on X86_EXTENDED_PLATFORM
8f9ca475
IM
442 ---help---
443 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
d49c4288
YL
444 subarchitectures. It is intended for a generic binary kernel.
445 if you select them all, kernel will probe it one by one. and will
446 fallback to default.
447
c5c606d9 448# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 449
506f1d07
SR
450config X86_NUMAQ
451 bool "NUMAQ (IBM/Sequent)"
e0c7ae37 452 depends on X86_32_NON_STANDARD
a92d152e 453 depends on PCI
506f1d07 454 select NUMA
9c398017 455 select X86_MPPARSE
8f9ca475 456 ---help---
d49c4288
YL
457 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
458 NUMA multiquad box. This changes the way that processors are
459 bootstrapped, and uses Clustered Logical APIC addressing mode instead
460 of Flat Logical. You will need a new lynxer.elf file to flash your
461 firmware with - send email to <Martin.Bligh@us.ibm.com>.
506f1d07 462
d949f36f 463config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 464 def_bool y
d949f36f
LT
465 # MCE code calls memory_failure():
466 depends on X86_MCE
467 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
468 depends on !X86_NUMAQ
469 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
470 depends on X86_64 || !SPARSEMEM
471 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 472
1b84e1c8
IM
473config X86_VISWS
474 bool "SGI 320/540 (Visual Workstation)"
c5c606d9
RT
475 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
476 depends on X86_32_NON_STANDARD
477 ---help---
1b84e1c8
IM
478 The SGI Visual Workstation series is an IA32-based workstation
479 based on SGI systems chips with some legacy PC hardware attached.
480
481 Say Y here to create a kernel to run on the SGI 320 or 540.
482
483 A kernel compiled for the Visual Workstation will run on general
484 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
485
9c398017
IM
486config X86_SUMMIT
487 bool "Summit/EXA (IBM x440)"
e0c7ae37 488 depends on X86_32_NON_STANDARD
8f9ca475 489 ---help---
9c398017
IM
490 This option is needed for IBM systems that use the Summit/EXA chipset.
491 In particular, it is needed for the x440.
1f972768 492
9c398017 493config X86_ES7000
c5c606d9 494 bool "Unisys ES7000 IA32 series"
26f7ef14 495 depends on X86_32_NON_STANDARD && X86_BIGSMP
8f9ca475 496 ---help---
9c398017
IM
497 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
498 supposed to run on an IA32-based Unisys ES7000 system.
499
ae1e9130 500config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
501 def_bool y
502 prompt "Single-depth WCHAN output"
a87d0914 503 depends on X86
8f9ca475 504 ---help---
506f1d07
SR
505 Calculate simpler /proc/<PID>/wchan values. If this option
506 is disabled then wchan values will recurse back to the
507 caller function. This provides more accurate wchan values,
508 at the expense of slightly more scheduling overhead.
509
510 If in doubt, say "Y".
511
506f1d07
SR
512menuconfig PARAVIRT_GUEST
513 bool "Paravirtualized guest support"
8f9ca475 514 ---help---
506f1d07
SR
515 Say Y here to get to see options related to running Linux under
516 various hypervisors. This option alone does not add any kernel code.
517
518 If you say N, all options in this submenu will be skipped and disabled.
519
520if PARAVIRT_GUEST
521
522source "arch/x86/xen/Kconfig"
523
524config VMI
d0153ca3 525 bool "VMI Guest support (DEPRECATED)"
506f1d07 526 select PARAVIRT
42d545c9 527 depends on X86_32
8f9ca475 528 ---help---
506f1d07
SR
529 VMI provides a paravirtualized interface to the VMware ESX server
530 (it could be used by other hypervisors in theory too, but is not
531 at the moment), by linking the kernel to a GPL-ed ROM module
532 provided by the hypervisor.
533
d0153ca3
AK
534 As of September 2009, VMware has started a phased retirement
535 of this feature from VMware's products. Please see
536 feature-removal-schedule.txt for details. If you are
537 planning to enable this option, please note that you cannot
538 live migrate a VMI enabled VM to a future VMware product,
539 which doesn't support VMI. So if you expect your kernel to
540 seamlessly migrate to newer VMware products, keep this
541 disabled.
542
790c73f6
GOC
543config KVM_CLOCK
544 bool "KVM paravirtualized clock"
545 select PARAVIRT
f6e16d5a 546 select PARAVIRT_CLOCK
8f9ca475 547 ---help---
790c73f6
GOC
548 Turning on this option will allow you to run a paravirtualized clock
549 when running over the KVM hypervisor. Instead of relying on a PIT
550 (or probably other) emulation by the underlying device model, the host
551 provides the guest with timing infrastructure such as time of day, and
552 system time
553
0cf1bfd2
MT
554config KVM_GUEST
555 bool "KVM Guest support"
556 select PARAVIRT
8f9ca475
IM
557 ---help---
558 This option enables various optimizations for running under the KVM
559 hypervisor.
0cf1bfd2 560
506f1d07
SR
561source "arch/x86/lguest/Kconfig"
562
e61bd94a
EPH
563config PARAVIRT
564 bool "Enable paravirtualization code"
8f9ca475 565 ---help---
e61bd94a
EPH
566 This changes the kernel so it can modify itself when it is run
567 under a hypervisor, potentially improving performance significantly
568 over full virtualization. However, when run without a hypervisor
569 the kernel is theoretically slower and slightly larger.
570
b4ecc126
JF
571config PARAVIRT_SPINLOCKS
572 bool "Paravirtualization layer for spinlocks"
573 depends on PARAVIRT && SMP && EXPERIMENTAL
574 ---help---
575 Paravirtualized spinlocks allow a pvops backend to replace the
576 spinlock implementation with something virtualization-friendly
577 (for example, block the virtual CPU rather than spinning).
578
579 Unfortunately the downside is an up to 5% performance hit on
580 native kernels, with various workloads.
581
582 If you are unsure how to answer this question, answer N.
583
7af192c9
GH
584config PARAVIRT_CLOCK
585 bool
7af192c9 586
506f1d07
SR
587endif
588
97349135 589config PARAVIRT_DEBUG
8f9ca475
IM
590 bool "paravirt-ops debugging"
591 depends on PARAVIRT && DEBUG_KERNEL
592 ---help---
593 Enable to debug paravirt_ops internals. Specifically, BUG if
594 a paravirt_op is missing when it is called.
97349135 595
08677214
YL
596config NO_BOOTMEM
597 default y
598 bool "Disable Bootmem code"
08677214
YL
599 ---help---
600 Use early_res directly instead of bootmem before slab is ready.
601 - allocator (buddy) [generic]
602 - early allocator (bootmem) [generic]
603 - very early allocator (reserve_early*()) [x86]
604 - very very early allocator (early brk model) [x86]
605 So reduce one layer between early allocator to final allocator
606
607
03273184
YL
608config MEMTEST
609 bool "Memtest"
8f9ca475 610 ---help---
c64df707 611 This option adds a kernel parameter 'memtest', which allows memtest
03273184 612 to be set.
8f9ca475
IM
613 memtest=0, mean disabled; -- default
614 memtest=1, mean do 1 test pattern;
615 ...
616 memtest=4, mean do 4 test patterns.
aba3728c 617 If you are unsure how to answer this question, answer N.
506f1d07
SR
618
619config X86_SUMMIT_NUMA
3c2362e6 620 def_bool y
e0c7ae37 621 depends on X86_32 && NUMA && X86_32_NON_STANDARD
506f1d07
SR
622
623config X86_CYCLONE_TIMER
3c2362e6 624 def_bool y
e0c7ae37 625 depends on X86_32_NON_STANDARD
506f1d07 626
506f1d07
SR
627source "arch/x86/Kconfig.cpu"
628
629config HPET_TIMER
3c2362e6 630 def_bool X86_64
506f1d07 631 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
632 ---help---
633 Use the IA-PC HPET (High Precision Event Timer) to manage
634 time in preference to the PIT and RTC, if a HPET is
635 present.
636 HPET is the next generation timer replacing legacy 8254s.
637 The HPET provides a stable time base on SMP
638 systems, unlike the TSC, but it is more expensive to access,
639 as it is off-chip. You can find the HPET spec at
640 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
506f1d07 641
8f9ca475
IM
642 You can safely choose Y here. However, HPET will only be
643 activated if the platform and the BIOS support this feature.
644 Otherwise the 8254 will be used for timing services.
506f1d07 645
8f9ca475 646 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
647
648config HPET_EMULATE_RTC
3c2362e6 649 def_bool y
9d8af78b 650 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 651
bb24c471
JP
652config APB_TIMER
653 def_bool y if MRST
654 prompt "Langwell APB Timer Support" if X86_MRST
655 help
656 APB timer is the replacement for 8254, HPET on X86 MID platforms.
657 The APBT provides a stable time base on SMP
658 systems, unlike the TSC, but it is more expensive to access,
659 as it is off-chip. APB timers are always running regardless of CPU
660 C states, they are used as per CPU clockevent device when possible.
661
506f1d07
SR
662# Mark as embedded because too many people got it wrong.
663# The code disables itself when not needed.
7ae9392c
TP
664config DMI
665 default y
666 bool "Enable DMI scanning" if EMBEDDED
8f9ca475 667 ---help---
7ae9392c
TP
668 Enabled scanning of DMI to identify machine quirks. Say Y
669 here unless you have verified that your setup is not
670 affected by entries in the DMI blacklist. Required by PNP
671 BIOS code.
672
506f1d07
SR
673config GART_IOMMU
674 bool "GART IOMMU support" if EMBEDDED
675 default y
676 select SWIOTLB
23ac4ae8 677 depends on X86_64 && PCI && AMD_NB
8f9ca475 678 ---help---
506f1d07
SR
679 Support for full DMA access of devices with 32bit memory access only
680 on systems with more than 3GB. This is usually needed for USB,
681 sound, many IDE/SATA chipsets and some other devices.
682 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
683 based hardware IOMMU and a software bounce buffer based IOMMU used
684 on Intel systems and as fallback.
685 The code is only active when needed (enough memory and limited
686 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
687 too.
688
689config CALGARY_IOMMU
690 bool "IBM Calgary IOMMU support"
691 select SWIOTLB
692 depends on X86_64 && PCI && EXPERIMENTAL
8f9ca475 693 ---help---
506f1d07
SR
694 Support for hardware IOMMUs in IBM's xSeries x366 and x460
695 systems. Needed to run systems with more than 3GB of memory
696 properly with 32-bit PCI devices that do not support DAC
697 (Double Address Cycle). Calgary also supports bus level
698 isolation, where all DMAs pass through the IOMMU. This
699 prevents them from going anywhere except their intended
700 destination. This catches hard-to-find kernel bugs and
701 mis-behaving drivers and devices that do not use the DMA-API
702 properly to set up their DMA buffers. The IOMMU can be
703 turned off at boot time with the iommu=off parameter.
704 Normally the kernel will make the right choice by itself.
705 If unsure, say Y.
706
707config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
708 def_bool y
709 prompt "Should Calgary be enabled by default?"
506f1d07 710 depends on CALGARY_IOMMU
8f9ca475 711 ---help---
506f1d07
SR
712 Should Calgary be enabled by default? if you choose 'y', Calgary
713 will be used (if it exists). If you choose 'n', Calgary will not be
714 used even if it exists. If you choose 'n' and would like to use
715 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
716 If unsure, say Y.
717
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JR
718config AMD_IOMMU
719 bool "AMD IOMMU support"
07c40e8a 720 select SWIOTLB
a80dc3e0 721 select PCI_MSI
24d2ba0a 722 depends on X86_64 && PCI && ACPI
8f9ca475 723 ---help---
18d22200
JR
724 With this option you can enable support for AMD IOMMU hardware in
725 your system. An IOMMU is a hardware component which provides
726 remapping of DMA memory accesses from devices. With an AMD IOMMU you
727 can isolate the the DMA memory of different devices and protect the
728 system from misbehaving device drivers or hardware.
729
730 You can find out if your system has an AMD IOMMU if you look into
731 your BIOS for an option to enable it or if you have an IVRS ACPI
732 table.
2b188723 733
2e117604
JR
734config AMD_IOMMU_STATS
735 bool "Export AMD IOMMU statistics to debugfs"
736 depends on AMD_IOMMU
737 select DEBUG_FS
8f9ca475 738 ---help---
2e117604
JR
739 This option enables code in the AMD IOMMU driver to collect various
740 statistics about whats happening in the driver and exports that
741 information to userspace via debugfs.
742 If unsure, say N.
743
506f1d07
SR
744# need this always selected by IOMMU for the VIA workaround
745config SWIOTLB
a1afd01c 746 def_bool y if X86_64
8f9ca475 747 ---help---
506f1d07
SR
748 Support for software bounce buffers used on x86-64 systems
749 which don't have a hardware IOMMU (e.g. the current generation
750 of Intel's x86-64 CPUs). Using this PCI devices which can only
751 access 32-bits of memory can be used on systems with more than
752 3 GB of memory. If unsure, say Y.
753
a8522509 754config IOMMU_HELPER
18b743dc 755 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
d25e26b6 756
1aaf1183
JR
757config IOMMU_API
758 def_bool (AMD_IOMMU || DMAR)
759
1184dc2f 760config MAXSMP
ddb0c5a6 761 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
36f5101a
MT
762 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
763 select CPUMASK_OFFSTACK
8f9ca475 764 ---help---
ddb0c5a6 765 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 766 If unsure, say N.
506f1d07
SR
767
768config NR_CPUS
36f5101a 769 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 770 range 2 8 if SMP && X86_32 && !X86_BIGSMP
36f5101a 771 range 2 512 if SMP && !MAXSMP
78637a97 772 default "1" if !SMP
d25e26b6 773 default "4096" if MAXSMP
78637a97
MT
774 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
775 default "8" if SMP
8f9ca475 776 ---help---
506f1d07 777 This allows you to specify the maximum number of CPUs which this
d25e26b6 778 kernel will support. The maximum supported value is 512 and the
506f1d07
SR
779 minimum value which makes sense is 2.
780
781 This is purely to save memory - each supported CPU adds
782 approximately eight kilobytes to the kernel image.
783
784config SCHED_SMT
785 bool "SMT (Hyperthreading) scheduler support"
b089c12b 786 depends on X86_HT
8f9ca475 787 ---help---
506f1d07
SR
788 SMT scheduler support improves the CPU scheduler's decision making
789 when dealing with Intel Pentium 4 chips with HyperThreading at a
790 cost of slightly increased overhead in some places. If unsure say
791 N here.
792
793config SCHED_MC
3c2362e6
HH
794 def_bool y
795 prompt "Multi-core scheduler support"
b089c12b 796 depends on X86_HT
8f9ca475 797 ---help---
506f1d07
SR
798 Multi-core scheduler support improves the CPU scheduler's decision
799 making when dealing with multi-core CPU chips at a cost of slightly
800 increased overhead in some places. If unsure say N here.
801
e82b8e4e
VP
802config IRQ_TIME_ACCOUNTING
803 bool "Fine granularity task level IRQ time accounting"
804 default n
805 ---help---
806 Select this option to enable fine granularity task irq time
807 accounting. This is done by reading a timestamp on each
808 transitions between softirq and hardirq state, so there can be a
809 small performance impact.
810
811 If in doubt, say N here.
812
506f1d07
SR
813source "kernel/Kconfig.preempt"
814
815config X86_UP_APIC
816 bool "Local APIC support on uniprocessors"
e0c7ae37 817 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 818 ---help---
506f1d07
SR
819 A local APIC (Advanced Programmable Interrupt Controller) is an
820 integrated interrupt controller in the CPU. If you have a single-CPU
821 system which has a processor with a local APIC, you can say Y here to
822 enable and use it. If you say Y here even though your machine doesn't
823 have a local APIC, then the kernel will still run with no slowdown at
824 all. The local APIC supports CPU-generated self-interrupts (timer,
825 performance counters), and the NMI watchdog which detects hard
826 lockups.
827
828config X86_UP_IOAPIC
829 bool "IO-APIC support on uniprocessors"
830 depends on X86_UP_APIC
8f9ca475 831 ---help---
506f1d07
SR
832 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
833 SMP-capable replacement for PC-style interrupt controllers. Most
834 SMP systems and many recent uniprocessor systems have one.
835
836 If you have a single-CPU system with an IO-APIC, you can say Y here
837 to use it. If you say Y here even though your machine doesn't have
838 an IO-APIC, then the kernel will still run with no slowdown at all.
839
840config X86_LOCAL_APIC
3c2362e6 841 def_bool y
e0c7ae37 842 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
506f1d07
SR
843
844config X86_IO_APIC
3c2362e6 845 def_bool y
e0c7ae37 846 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
506f1d07
SR
847
848config X86_VISWS_APIC
3c2362e6 849 def_bool y
506f1d07 850 depends on X86_32 && X86_VISWS
506f1d07 851
41b9eb26
SA
852config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
853 bool "Reroute for broken boot IRQs"
41b9eb26 854 depends on X86_IO_APIC
8f9ca475 855 ---help---
41b9eb26
SA
856 This option enables a workaround that fixes a source of
857 spurious interrupts. This is recommended when threaded
858 interrupt handling is used on systems where the generation of
859 superfluous "boot interrupts" cannot be disabled.
860
861 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
862 entry in the chipset's IO-APIC is masked (as, e.g. the RT
863 kernel does during interrupt handling). On chipsets where this
864 boot IRQ generation cannot be disabled, this workaround keeps
865 the original IRQ line masked so that only the equivalent "boot
866 IRQ" is delivered to the CPUs. The workaround also tells the
867 kernel to set up the IRQ handler on the boot IRQ line. In this
868 way only one interrupt is delivered to the kernel. Otherwise
869 the spurious second interrupt may cause the kernel to bring
870 down (vital) interrupt lines.
871
872 Only affects "broken" chipsets. Interrupt sharing may be
873 increased on these systems.
874
506f1d07 875config X86_MCE
bab9bc65 876 bool "Machine Check / overheating reporting"
506f1d07 877 ---help---
bab9bc65
AK
878 Machine Check support allows the processor to notify the
879 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 880 The action the kernel takes depends on the severity of the problem,
bab9bc65 881 ranging from warning messages to halting the machine.
4efc0670 882
506f1d07 883config X86_MCE_INTEL
3c2362e6
HH
884 def_bool y
885 prompt "Intel MCE features"
c1ebf835 886 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 887 ---help---
506f1d07
SR
888 Additional support for intel specific MCE features such as
889 the thermal monitor.
890
891config X86_MCE_AMD
3c2362e6
HH
892 def_bool y
893 prompt "AMD MCE features"
c1ebf835 894 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 895 ---help---
506f1d07
SR
896 Additional support for AMD specific MCE features such as
897 the DRAM Error Threshold.
898
4efc0670 899config X86_ANCIENT_MCE
6fc108a0 900 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 901 depends on X86_32 && X86_MCE
cd13adcc
HS
902 ---help---
903 Include support for machine check handling on old Pentium 5 or WinChip
904 systems. These typically need to be enabled explicitely on the command
905 line.
4efc0670 906
b2762686
AK
907config X86_MCE_THRESHOLD
908 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 909 def_bool y
b2762686 910
ea149b36 911config X86_MCE_INJECT
c1ebf835 912 depends on X86_MCE
ea149b36
AK
913 tristate "Machine check injector support"
914 ---help---
915 Provide support for injecting machine checks for testing purposes.
916 If you don't know what a machine check is and you don't do kernel
917 QA it is safe to say n.
918
4efc0670
AK
919config X86_THERMAL_VECTOR
920 def_bool y
5bb38adc 921 depends on X86_MCE_INTEL
4efc0670 922
506f1d07
SR
923config VM86
924 bool "Enable VM86 support" if EMBEDDED
925 default y
926 depends on X86_32
8f9ca475
IM
927 ---help---
928 This option is required by programs like DOSEMU to run 16-bit legacy
506f1d07 929 code on X86 processors. It also may be needed by software like
8f9ca475
IM
930 XFree86 to initialize some video cards via BIOS. Disabling this
931 option saves about 6k.
506f1d07
SR
932
933config TOSHIBA
934 tristate "Toshiba Laptop support"
935 depends on X86_32
936 ---help---
937 This adds a driver to safely access the System Management Mode of
938 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
939 not work on models with a Phoenix BIOS. The System Management Mode
940 is used to set the BIOS and power saving options on Toshiba portables.
941
942 For information on utilities to make use of this driver see the
943 Toshiba Linux utilities web site at:
944 <http://www.buzzard.org.uk/toshiba/>.
945
946 Say Y if you intend to run this kernel on a Toshiba portable.
947 Say N otherwise.
948
949config I8K
950 tristate "Dell laptop support"
506f1d07
SR
951 ---help---
952 This adds a driver to safely access the System Management Mode
953 of the CPU on the Dell Inspiron 8000. The System Management Mode
954 is used to read cpu temperature and cooling fan status and to
955 control the fans on the I8K portables.
956
957 This driver has been tested only on the Inspiron 8000 but it may
958 also work with other Dell laptops. You can force loading on other
959 models by passing the parameter `force=1' to the module. Use at
960 your own risk.
961
962 For information on utilities to make use of this driver see the
963 I8K Linux utilities web site at:
964 <http://people.debian.org/~dz/i8k/>
965
966 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
967 Say N otherwise.
968
969config X86_REBOOTFIXUPS
9ba16087
JB
970 bool "Enable X86 board specific fixups for reboot"
971 depends on X86_32
506f1d07
SR
972 ---help---
973 This enables chipset and/or board specific fixups to be done
974 in order to get reboot to work correctly. This is only needed on
975 some combinations of hardware and BIOS. The symptom, for which
976 this config is intended, is when reboot ends with a stalled/hung
977 system.
978
979 Currently, the only fixup is for the Geode machines using
5e3a77e9 980 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
981
982 Say Y if you want to enable the fixup. Currently, it's safe to
983 enable this option even if you don't need it.
984 Say N otherwise.
985
986config MICROCODE
8d86f390 987 tristate "/dev/cpu/microcode - microcode support"
506f1d07
SR
988 select FW_LOADER
989 ---help---
990 If you say Y here, you will be able to update the microcode on
80cc9f10
PO
991 certain Intel and AMD processors. The Intel support is for the
992 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
993 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
994 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
995 You will obviously need the actual microcode binary data itself
996 which is not shipped with the Linux kernel.
506f1d07 997
8d86f390
PO
998 This option selects the general module only, you need to select
999 at least one vendor specific module as well.
506f1d07
SR
1000
1001 To compile this driver as a module, choose M here: the
1002 module will be called microcode.
1003
8d86f390 1004config MICROCODE_INTEL
8f9ca475
IM
1005 bool "Intel microcode patch loading support"
1006 depends on MICROCODE
1007 default MICROCODE
1008 select FW_LOADER
1009 ---help---
1010 This options enables microcode patch loading support for Intel
1011 processors.
1012
1013 For latest news and information on obtaining all the required
1014 Intel ingredients for this driver, check:
1015 <http://www.urbanmyth.org/microcode/>.
8d86f390 1016
80cc9f10 1017config MICROCODE_AMD
8f9ca475
IM
1018 bool "AMD microcode patch loading support"
1019 depends on MICROCODE
1020 select FW_LOADER
1021 ---help---
1022 If you select this option, microcode patch loading support for AMD
1023 processors will be enabled.
80cc9f10 1024
8f9ca475 1025config MICROCODE_OLD_INTERFACE
3c2362e6 1026 def_bool y
506f1d07 1027 depends on MICROCODE
506f1d07
SR
1028
1029config X86_MSR
1030 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1031 ---help---
506f1d07
SR
1032 This device gives privileged processes access to the x86
1033 Model-Specific Registers (MSRs). It is a character device with
1034 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1035 MSR accesses are directed to a specific CPU on multi-processor
1036 systems.
1037
1038config X86_CPUID
1039 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1040 ---help---
506f1d07
SR
1041 This device gives processes access to the x86 CPUID instruction to
1042 be executed on a specific processor. It is a character device
1043 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1044 /dev/cpu/31/cpuid.
1045
1046choice
1047 prompt "High Memory Support"
506f1d07 1048 default HIGHMEM64G if X86_NUMAQ
6fc108a0 1049 default HIGHMEM4G
506f1d07
SR
1050 depends on X86_32
1051
1052config NOHIGHMEM
1053 bool "off"
1054 depends on !X86_NUMAQ
1055 ---help---
1056 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1057 However, the address space of 32-bit x86 processors is only 4
1058 Gigabytes large. That means that, if you have a large amount of
1059 physical memory, not all of it can be "permanently mapped" by the
1060 kernel. The physical memory that's not permanently mapped is called
1061 "high memory".
1062
1063 If you are compiling a kernel which will never run on a machine with
1064 more than 1 Gigabyte total physical RAM, answer "off" here (default
1065 choice and suitable for most users). This will result in a "3GB/1GB"
1066 split: 3GB are mapped so that each process sees a 3GB virtual memory
1067 space and the remaining part of the 4GB virtual memory space is used
1068 by the kernel to permanently map as much physical memory as
1069 possible.
1070
1071 If the machine has between 1 and 4 Gigabytes physical RAM, then
1072 answer "4GB" here.
1073
1074 If more than 4 Gigabytes is used then answer "64GB" here. This
1075 selection turns Intel PAE (Physical Address Extension) mode on.
1076 PAE implements 3-level paging on IA32 processors. PAE is fully
1077 supported by Linux, PAE mode is implemented on all recent Intel
1078 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1079 then the kernel will not boot on CPUs that don't support PAE!
1080
1081 The actual amount of total physical memory will either be
1082 auto detected or can be forced by using a kernel command line option
1083 such as "mem=256M". (Try "man bootparam" or see the documentation of
1084 your boot loader (lilo or loadlin) about how to pass options to the
1085 kernel at boot time.)
1086
1087 If unsure, say "off".
1088
1089config HIGHMEM4G
1090 bool "4GB"
1091 depends on !X86_NUMAQ
8f9ca475 1092 ---help---
506f1d07
SR
1093 Select this if you have a 32-bit processor and between 1 and 4
1094 gigabytes of physical RAM.
1095
1096config HIGHMEM64G
1097 bool "64GB"
1098 depends on !M386 && !M486
1099 select X86_PAE
8f9ca475 1100 ---help---
506f1d07
SR
1101 Select this if you have a 32-bit processor and more than 4
1102 gigabytes of physical RAM.
1103
1104endchoice
1105
1106choice
1107 depends on EXPERIMENTAL
1108 prompt "Memory split" if EMBEDDED
1109 default VMSPLIT_3G
1110 depends on X86_32
8f9ca475 1111 ---help---
506f1d07
SR
1112 Select the desired split between kernel and user memory.
1113
1114 If the address range available to the kernel is less than the
1115 physical memory installed, the remaining memory will be available
1116 as "high memory". Accessing high memory is a little more costly
1117 than low memory, as it needs to be mapped into the kernel first.
1118 Note that increasing the kernel address space limits the range
1119 available to user programs, making the address space there
1120 tighter. Selecting anything other than the default 3G/1G split
1121 will also likely make your kernel incompatible with binary-only
1122 kernel modules.
1123
1124 If you are not absolutely sure what you are doing, leave this
1125 option alone!
1126
1127 config VMSPLIT_3G
1128 bool "3G/1G user/kernel split"
1129 config VMSPLIT_3G_OPT
1130 depends on !X86_PAE
1131 bool "3G/1G user/kernel split (for full 1G low memory)"
1132 config VMSPLIT_2G
1133 bool "2G/2G user/kernel split"
1134 config VMSPLIT_2G_OPT
1135 depends on !X86_PAE
1136 bool "2G/2G user/kernel split (for full 2G low memory)"
1137 config VMSPLIT_1G
1138 bool "1G/3G user/kernel split"
1139endchoice
1140
1141config PAGE_OFFSET
1142 hex
1143 default 0xB0000000 if VMSPLIT_3G_OPT
1144 default 0x80000000 if VMSPLIT_2G
1145 default 0x78000000 if VMSPLIT_2G_OPT
1146 default 0x40000000 if VMSPLIT_1G
1147 default 0xC0000000
1148 depends on X86_32
1149
1150config HIGHMEM
3c2362e6 1151 def_bool y
506f1d07 1152 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1153
1154config X86_PAE
9ba16087 1155 bool "PAE (Physical Address Extension) Support"
506f1d07 1156 depends on X86_32 && !HIGHMEM4G
8f9ca475 1157 ---help---
506f1d07
SR
1158 PAE is required for NX support, and furthermore enables
1159 larger swapspace support for non-overcommit purposes. It
1160 has the cost of more pagetable lookup overhead, and also
1161 consumes more pagetable space per process.
1162
600715dc 1163config ARCH_PHYS_ADDR_T_64BIT
8f9ca475 1164 def_bool X86_64 || X86_PAE
600715dc 1165
9e899816
NP
1166config DIRECT_GBPAGES
1167 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1168 default y
1169 depends on X86_64
8f9ca475 1170 ---help---
9e899816
NP
1171 Allow the kernel linear mapping to use 1GB pages on CPUs that
1172 support it. This can improve the kernel's performance a tiny bit by
1173 reducing TLB pressure. If in doubt, say "Y".
1174
506f1d07
SR
1175# Common NUMA Features
1176config NUMA
fd51b2d7 1177 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1178 depends on SMP
604d2055 1179 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
0699eae1 1180 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
8f9ca475 1181 ---help---
506f1d07 1182 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1183
506f1d07
SR
1184 The kernel will try to allocate memory used by a CPU on the
1185 local memory controller of the CPU and add some more
1186 NUMA awareness to the kernel.
1187
c280ea5e 1188 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1189 (or later), AMD Opteron, or EM64T NUMA.
1190
1191 For 32-bit this is only needed on (rare) 32-bit-only platforms
1192 that support NUMA topologies, such as NUMAQ / Summit, or if you
1193 boot a 32-bit kernel on a 64-bit NUMA platform.
1194
1195 Otherwise, you should say N.
506f1d07
SR
1196
1197comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1198 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1199
1200config K8_NUMA
3c2362e6
HH
1201 def_bool y
1202 prompt "Old style AMD Opteron NUMA detection"
1203 depends on X86_64 && NUMA && PCI
8f9ca475
IM
1204 ---help---
1205 Enable K8 NUMA node topology detection. You should say Y here if
1206 you have a multi processor AMD K8 system. This uses an old
1207 method to read the NUMA configuration directly from the builtin
1208 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1209 instead, which also takes priority if both are compiled in.
506f1d07
SR
1210
1211config X86_64_ACPI_NUMA
3c2362e6
HH
1212 def_bool y
1213 prompt "ACPI NUMA detection"
506f1d07
SR
1214 depends on X86_64 && NUMA && ACPI && PCI
1215 select ACPI_NUMA
8f9ca475 1216 ---help---
506f1d07
SR
1217 Enable ACPI SRAT based node topology detection.
1218
6ec6e0d9
SS
1219# Some NUMA nodes have memory ranges that span
1220# other nodes. Even though a pfn is valid and
1221# between a node's start and end pfns, it may not
1222# reside on that node. See memmap_init_zone()
1223# for details.
1224config NODES_SPAN_OTHER_NODES
1225 def_bool y
1226 depends on X86_64_ACPI_NUMA
1227
506f1d07
SR
1228config NUMA_EMU
1229 bool "NUMA emulation"
1230 depends on X86_64 && NUMA
8f9ca475 1231 ---help---
506f1d07
SR
1232 Enable NUMA emulation. A flat machine will be split
1233 into virtual nodes when booted with "numa=fake=N", where N is the
1234 number of nodes. This is only useful for debugging.
1235
1236config NODES_SHIFT
d25e26b6 1237 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1238 range 1 10
1239 default "10" if MAXSMP
506f1d07
SR
1240 default "6" if X86_64
1241 default "4" if X86_NUMAQ
1242 default "3"
1243 depends on NEED_MULTIPLE_NODES
8f9ca475 1244 ---help---
1184dc2f 1245 Specify the maximum number of NUMA Nodes available on the target
692105b8 1246 system. Increases memory reserved to accommodate various tables.
506f1d07 1247
c1329375 1248config HAVE_ARCH_BOOTMEM
3c2362e6 1249 def_bool y
506f1d07 1250 depends on X86_32 && NUMA
506f1d07
SR
1251
1252config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1253 def_bool y
506f1d07 1254 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1255
1256config NEED_NODE_MEMMAP_SIZE
3c2362e6 1257 def_bool y
506f1d07 1258 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07
SR
1259
1260config HAVE_ARCH_ALLOC_REMAP
3c2362e6 1261 def_bool y
506f1d07 1262 depends on X86_32 && NUMA
506f1d07
SR
1263
1264config ARCH_FLATMEM_ENABLE
1265 def_bool y
99809963 1266 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
506f1d07
SR
1267
1268config ARCH_DISCONTIGMEM_ENABLE
1269 def_bool y
b263295d 1270 depends on NUMA && X86_32
506f1d07
SR
1271
1272config ARCH_DISCONTIGMEM_DEFAULT
1273 def_bool y
b263295d
CL
1274 depends on NUMA && X86_32
1275
9492587c
KH
1276config ARCH_PROC_KCORE_TEXT
1277 def_bool y
1278 depends on X86_64 && PROC_KCORE
1279
b263295d
CL
1280config ARCH_SPARSEMEM_DEFAULT
1281 def_bool y
1282 depends on X86_64
506f1d07
SR
1283
1284config ARCH_SPARSEMEM_ENABLE
1285 def_bool y
4272ebfb 1286 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
506f1d07
SR
1287 select SPARSEMEM_STATIC if X86_32
1288 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1289
1290config ARCH_SELECT_MEMORY_MODEL
1291 def_bool y
b263295d 1292 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1293
1294config ARCH_MEMORY_PROBE
1295 def_bool X86_64
1296 depends on MEMORY_HOTPLUG
1297
a29815a3
AK
1298config ILLEGAL_POINTER_VALUE
1299 hex
1300 default 0 if X86_32
1301 default 0xdead000000000000 if X86_64
1302
506f1d07
SR
1303source "mm/Kconfig"
1304
1305config HIGHPTE
1306 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1307 depends on HIGHMEM
8f9ca475 1308 ---help---
506f1d07
SR
1309 The VM uses one page table entry for each page of physical memory.
1310 For systems with a lot of RAM, this can be wasteful of precious
1311 low memory. Setting this option will put user-space page table
1312 entries in high memory.
1313
9f077871 1314config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1315 bool "Check for low memory corruption"
1316 ---help---
1317 Periodically check for memory corruption in low memory, which
1318 is suspected to be caused by BIOS. Even when enabled in the
1319 configuration, it is disabled at runtime. Enable it by
1320 setting "memory_corruption_check=1" on the kernel command
1321 line. By default it scans the low 64k of memory every 60
1322 seconds; see the memory_corruption_check_size and
1323 memory_corruption_check_period parameters in
1324 Documentation/kernel-parameters.txt to adjust this.
1325
1326 When enabled with the default parameters, this option has
1327 almost no overhead, as it reserves a relatively small amount
1328 of memory and scans it infrequently. It both detects corruption
1329 and prevents it from affecting the running system.
1330
1331 It is, however, intended as a diagnostic tool; if repeatable
1332 BIOS-originated corruption always affects the same memory,
1333 you can use memmap= to prevent the kernel from using that
1334 memory.
9f077871 1335
c885df50 1336config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1337 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1338 depends on X86_CHECK_BIOS_CORRUPTION
1339 default y
8f9ca475
IM
1340 ---help---
1341 Set whether the default state of memory_corruption_check is
1342 on or off.
c885df50 1343
9ea77bdb 1344config X86_RESERVE_LOW
d0cd7425
PA
1345 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1346 default 64
1347 range 4 640
1348 ---help---
1349 Specify the amount of low memory to reserve for the BIOS.
1350
1351 The first page contains BIOS data structures that the kernel
1352 must not use, so that page must always be reserved.
1353
1354 By default we reserve the first 64K of physical RAM, as a
1355 number of BIOSes are known to corrupt that memory range
1356 during events such as suspend/resume or monitor cable
1357 insertion, so it must not be used by the kernel.
1358
1359 You can set this to 4 if you are absolutely sure that you
1360 trust the BIOS to get all its memory reservations and usages
1361 right. If you know your BIOS have problems beyond the
1362 default 64K area, you can set this to 640 to avoid using the
1363 entire low memory range.
1364
1365 If you have doubts about the BIOS (e.g. suspend/resume does
1366 not work or there's kernel crashes after certain hardware
1367 hotplug events) then you might want to enable
1368 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1369 typical corruption patterns.
1370
1371 Leave this to the default value of 64 if you are unsure.
fc381519 1372
506f1d07
SR
1373config MATH_EMULATION
1374 bool
1375 prompt "Math emulation" if X86_32
1376 ---help---
1377 Linux can emulate a math coprocessor (used for floating point
1378 operations) if you don't have one. 486DX and Pentium processors have
1379 a math coprocessor built in, 486SX and 386 do not, unless you added
1380 a 487DX or 387, respectively. (The messages during boot time can
1381 give you some hints here ["man dmesg"].) Everyone needs either a
1382 coprocessor or this emulation.
1383
1384 If you don't have a math coprocessor, you need to say Y here; if you
1385 say Y here even though you have a coprocessor, the coprocessor will
1386 be used nevertheless. (This behavior can be changed with the kernel
1387 command line option "no387", which comes handy if your coprocessor
1388 is broken. Try "man bootparam" or see the documentation of your boot
1389 loader (lilo or loadlin) about how to pass options to the kernel at
1390 boot time.) This means that it is a good idea to say Y here if you
1391 intend to use this kernel on different machines.
1392
1393 More information about the internals of the Linux math coprocessor
1394 emulation can be found in <file:arch/x86/math-emu/README>.
1395
1396 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1397 kernel, it won't hurt.
1398
1399config MTRR
6fc108a0 1400 def_bool y
c03cb314 1401 prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
506f1d07
SR
1402 ---help---
1403 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1404 the Memory Type Range Registers (MTRRs) may be used to control
1405 processor access to memory ranges. This is most useful if you have
1406 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1407 allows bus write transfers to be combined into a larger transfer
1408 before bursting over the PCI/AGP bus. This can increase performance
1409 of image write operations 2.5 times or more. Saying Y here creates a
1410 /proc/mtrr file which may be used to manipulate your processor's
1411 MTRRs. Typically the X server should use this.
1412
1413 This code has a reasonably generic interface so that similar
1414 control registers on other processors can be easily supported
1415 as well:
1416
1417 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1418 Registers (ARRs) which provide a similar functionality to MTRRs. For
1419 these, the ARRs are used to emulate the MTRRs.
1420 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1421 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1422 write-combining. All of these processors are supported by this code
1423 and it makes sense to say Y here if you have one of them.
1424
1425 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1426 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1427 can lead to all sorts of problems, so it's good to say Y here.
1428
1429 You can safely say Y even if your machine doesn't have MTRRs, you'll
1430 just add about 9 KB to your kernel.
1431
7225e751 1432 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1433
95ffa243 1434config MTRR_SANITIZER
2ffb3501 1435 def_bool y
95ffa243
YL
1436 prompt "MTRR cleanup support"
1437 depends on MTRR
8f9ca475 1438 ---help---
aba3728c
TG
1439 Convert MTRR layout from continuous to discrete, so X drivers can
1440 add writeback entries.
95ffa243 1441
aba3728c 1442 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1443 The largest mtrr entry size for a continuous block can be set with
aba3728c 1444 mtrr_chunk_size.
95ffa243 1445
2ffb3501 1446 If unsure, say Y.
95ffa243
YL
1447
1448config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1449 int "MTRR cleanup enable value (0-1)"
1450 range 0 1
1451 default "0"
95ffa243 1452 depends on MTRR_SANITIZER
8f9ca475 1453 ---help---
f5098d62 1454 Enable mtrr cleanup default value
95ffa243 1455
12031a62
YL
1456config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1457 int "MTRR cleanup spare reg num (0-7)"
1458 range 0 7
1459 default "1"
1460 depends on MTRR_SANITIZER
8f9ca475 1461 ---help---
12031a62 1462 mtrr cleanup spare entries default, it can be changed via
aba3728c 1463 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1464
2e5d9c85 1465config X86_PAT
6fc108a0 1466 def_bool y
c03cb314 1467 prompt "x86 PAT support" if EMBEDDED
2a8a2719 1468 depends on MTRR
8f9ca475 1469 ---help---
2e5d9c85 1470 Use PAT attributes to setup page level cache control.
042b78e4 1471
2e5d9c85 1472 PATs are the modern equivalents of MTRRs and are much more
1473 flexible than MTRRs.
1474
1475 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1476 spontaneous reboots) or a non-working video driver.
2e5d9c85 1477
1478 If unsure, say Y.
1479
46cf98cd
VP
1480config ARCH_USES_PG_UNCACHED
1481 def_bool y
1482 depends on X86_PAT
1483
506f1d07 1484config EFI
9ba16087 1485 bool "EFI runtime service support"
5b83683f 1486 depends on ACPI
506f1d07 1487 ---help---
8f9ca475
IM
1488 This enables the kernel to use EFI runtime services that are
1489 available (such as the EFI variable services).
506f1d07 1490
8f9ca475
IM
1491 This option is only useful on systems that have EFI firmware.
1492 In addition, you should use the latest ELILO loader available
1493 at <http://elilo.sourceforge.net> in order to take advantage
1494 of EFI runtime services. However, even with this option, the
1495 resultant kernel should continue to boot on existing non-EFI
1496 platforms.
506f1d07 1497
506f1d07 1498config SECCOMP
3c2362e6
HH
1499 def_bool y
1500 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1501 ---help---
506f1d07
SR
1502 This kernel feature is useful for number crunching applications
1503 that may need to compute untrusted bytecode during their
1504 execution. By using pipes or other transports made available to
1505 the process as file descriptors supporting the read/write
1506 syscalls, it's possible to isolate those applications in
1507 their own address space using seccomp. Once seccomp is
9c0bbee8 1508 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1509 and the task is only allowed to execute a few safe syscalls
1510 defined by each seccomp mode.
1511
1512 If unsure, say Y. Only embedded should say N here.
1513
1514config CC_STACKPROTECTOR
1515 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
8f9ca475
IM
1516 ---help---
1517 This option turns on the -fstack-protector GCC feature. This
113c5413
IM
1518 feature puts, at the beginning of functions, a canary value on
1519 the stack just before the return address, and validates
506f1d07
SR
1520 the value just before actually returning. Stack based buffer
1521 overflows (that need to overwrite this return address) now also
1522 overwrite the canary, which gets detected and the attack is then
1523 neutralized via a kernel panic.
1524
1525 This feature requires gcc version 4.2 or above, or a distribution
1526 gcc with the feature backported. Older versions are automatically
113c5413
IM
1527 detected and for those versions, this configuration option is
1528 ignored. (and a warning is printed during bootup)
506f1d07
SR
1529
1530source kernel/Kconfig.hz
1531
1532config KEXEC
1533 bool "kexec system call"
8f9ca475 1534 ---help---
506f1d07
SR
1535 kexec is a system call that implements the ability to shutdown your
1536 current kernel, and to start another kernel. It is like a reboot
1537 but it is independent of the system firmware. And like a reboot
1538 you can start any kernel with it, not just Linux.
1539
1540 The name comes from the similarity to the exec system call.
1541
1542 It is an ongoing process to be certain the hardware in a machine
1543 is properly shutdown, so do not be surprised if this code does not
1544 initially work for you. It may help to enable device hotplugging
1545 support. As of this writing the exact hardware interface is
1546 strongly in flux, so no good recommendation can be made.
1547
1548config CRASH_DUMP
04b69447 1549 bool "kernel crash dumps"
506f1d07 1550 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1551 ---help---
506f1d07
SR
1552 Generate crash dump after being started by kexec.
1553 This should be normally only set in special crash dump kernels
1554 which are loaded in the main kernel with kexec-tools into
1555 a specially reserved region and then later executed after
1556 a crash by kdump/kexec. The crash dump kernel must be compiled
1557 to a memory address not used by the main kernel or BIOS using
1558 PHYSICAL_START, or it must be built as a relocatable image
1559 (CONFIG_RELOCATABLE=y).
1560 For more details see Documentation/kdump/kdump.txt
1561
3ab83521
HY
1562config KEXEC_JUMP
1563 bool "kexec jump (EXPERIMENTAL)"
1564 depends on EXPERIMENTAL
fee7b0d8 1565 depends on KEXEC && HIBERNATION
8f9ca475 1566 ---help---
89081d17
HY
1567 Jump between original kernel and kexeced kernel and invoke
1568 code in physical address mode via KEXEC
3ab83521 1569
506f1d07
SR
1570config PHYSICAL_START
1571 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
ceefccc9 1572 default "0x1000000"
8f9ca475 1573 ---help---
506f1d07
SR
1574 This gives the physical address where the kernel is loaded.
1575
1576 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1577 bzImage will decompress itself to above physical address and
1578 run from there. Otherwise, bzImage will run from the address where
1579 it has been loaded by the boot loader and will ignore above physical
1580 address.
1581
1582 In normal kdump cases one does not have to set/change this option
1583 as now bzImage can be compiled as a completely relocatable image
1584 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1585 address. This option is mainly useful for the folks who don't want
1586 to use a bzImage for capturing the crash dump and want to use a
1587 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1588 to be specifically compiled to run from a specific memory area
1589 (normally a reserved region) and this option comes handy.
1590
ceefccc9
PA
1591 So if you are using bzImage for capturing the crash dump,
1592 leave the value here unchanged to 0x1000000 and set
1593 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1594 for capturing the crash dump change this value to start of
1595 the reserved region. In other words, it can be set based on
1596 the "X" value as specified in the "crashkernel=YM@XM"
1597 command line boot parameter passed to the panic-ed
1598 kernel. Please take a look at Documentation/kdump/kdump.txt
1599 for more details about crash dumps.
506f1d07
SR
1600
1601 Usage of bzImage for capturing the crash dump is recommended as
1602 one does not have to build two kernels. Same kernel can be used
1603 as production kernel and capture kernel. Above option should have
1604 gone away after relocatable bzImage support is introduced. But it
1605 is present because there are users out there who continue to use
1606 vmlinux for dump capture. This option should go away down the
1607 line.
1608
1609 Don't change this unless you know what you are doing.
1610
1611config RELOCATABLE
26717808
PA
1612 bool "Build a relocatable kernel"
1613 default y
8f9ca475 1614 ---help---
506f1d07
SR
1615 This builds a kernel image that retains relocation information
1616 so it can be loaded someplace besides the default 1MB.
1617 The relocations tend to make the kernel binary about 10% larger,
1618 but are discarded at runtime.
1619
1620 One use is for the kexec on panic case where the recovery kernel
1621 must live at a different physical address than the primary
1622 kernel.
1623
1624 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1625 it has been loaded at and the compile time physical address
1626 (CONFIG_PHYSICAL_START) is ignored.
1627
845adf72
PA
1628# Relocation on x86-32 needs some additional build support
1629config X86_NEED_RELOCS
1630 def_bool y
1631 depends on X86_32 && RELOCATABLE
1632
506f1d07 1633config PHYSICAL_ALIGN
6fc108a0 1634 hex "Alignment value to which kernel should be aligned" if X86_32
ceefccc9
PA
1635 default "0x1000000"
1636 range 0x2000 0x1000000
8f9ca475 1637 ---help---
506f1d07
SR
1638 This value puts the alignment restrictions on physical address
1639 where kernel is loaded and run from. Kernel is compiled for an
1640 address which meets above alignment restriction.
1641
1642 If bootloader loads the kernel at a non-aligned address and
1643 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1644 address aligned to above value and run from there.
1645
1646 If bootloader loads the kernel at a non-aligned address and
1647 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1648 load address and decompress itself to the address it has been
1649 compiled for and run from there. The address for which kernel is
1650 compiled already meets above alignment restrictions. Hence the
1651 end result is that kernel runs from a physical address meeting
1652 above alignment restrictions.
1653
1654 Don't change this unless you know what you are doing.
1655
1656config HOTPLUG_CPU
7c13e6a3 1657 bool "Support for hot-pluggable CPUs"
4b19ed91 1658 depends on SMP && HOTPLUG
506f1d07 1659 ---help---
7c13e6a3
DS
1660 Say Y here to allow turning CPUs off and on. CPUs can be
1661 controlled through /sys/devices/system/cpu.
1662 ( Note: power management support will enable this option
1663 automatically on SMP systems. )
1664 Say N if you want to disable CPU hotplug.
506f1d07
SR
1665
1666config COMPAT_VDSO
3c2362e6
HH
1667 def_bool y
1668 prompt "Compat VDSO support"
af65d648 1669 depends on X86_32 || IA32_EMULATION
8f9ca475 1670 ---help---
af65d648 1671 Map the 32-bit VDSO to the predictable old-style address too.
e84446de 1672
506f1d07
SR
1673 Say N here if you are running a sufficiently recent glibc
1674 version (2.3.3 or later), to remove the high-mapped
1675 VDSO mapping and to exclusively use the randomized VDSO.
1676
1677 If unsure, say Y.
1678
516cbf37
TB
1679config CMDLINE_BOOL
1680 bool "Built-in kernel command line"
8f9ca475 1681 ---help---
516cbf37
TB
1682 Allow for specifying boot arguments to the kernel at
1683 build time. On some systems (e.g. embedded ones), it is
1684 necessary or convenient to provide some or all of the
1685 kernel boot arguments with the kernel itself (that is,
1686 to not rely on the boot loader to provide them.)
1687
1688 To compile command line arguments into the kernel,
1689 set this option to 'Y', then fill in the
1690 the boot arguments in CONFIG_CMDLINE.
1691
1692 Systems with fully functional boot loaders (i.e. non-embedded)
1693 should leave this option set to 'N'.
1694
1695config CMDLINE
1696 string "Built-in kernel command string"
1697 depends on CMDLINE_BOOL
1698 default ""
8f9ca475 1699 ---help---
516cbf37
TB
1700 Enter arguments here that should be compiled into the kernel
1701 image and used at boot time. If the boot loader provides a
1702 command line at boot time, it is appended to this string to
1703 form the full kernel command line, when the system boots.
1704
1705 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1706 change this behavior.
1707
1708 In most cases, the command line (whether built-in or provided
1709 by the boot loader) should specify the device for the root
1710 file system.
1711
1712config CMDLINE_OVERRIDE
1713 bool "Built-in command line overrides boot loader arguments"
516cbf37 1714 depends on CMDLINE_BOOL
8f9ca475 1715 ---help---
516cbf37
TB
1716 Set this option to 'Y' to have the kernel ignore the boot loader
1717 command line, and use ONLY the built-in command line.
1718
1719 This is used to work around broken boot loaders. This should
1720 be set to 'N' under normal conditions.
1721
506f1d07
SR
1722endmenu
1723
1724config ARCH_ENABLE_MEMORY_HOTPLUG
1725 def_bool y
1726 depends on X86_64 || (X86_32 && HIGHMEM)
1727
35551053
GH
1728config ARCH_ENABLE_MEMORY_HOTREMOVE
1729 def_bool y
1730 depends on MEMORY_HOTPLUG
1731
506f1d07
SR
1732config HAVE_ARCH_EARLY_PFN_TO_NID
1733 def_bool X86_64
1734 depends on NUMA
1735
e534c7c5
LS
1736config USE_PERCPU_NUMA_NODE_ID
1737 def_bool X86_64
1738 depends on NUMA
1739
da85f865 1740menu "Power management and ACPI options"
e279b6c1
SR
1741
1742config ARCH_HIBERNATION_HEADER
3c2362e6 1743 def_bool y
e279b6c1 1744 depends on X86_64 && HIBERNATION
e279b6c1
SR
1745
1746source "kernel/power/Kconfig"
1747
1748source "drivers/acpi/Kconfig"
1749
efafc8b2
FT
1750source "drivers/sfi/Kconfig"
1751
a6b68076 1752config X86_APM_BOOT
6fc108a0 1753 def_bool y
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AK
1754 depends on APM || APM_MODULE
1755
e279b6c1
SR
1756menuconfig APM
1757 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 1758 depends on X86_32 && PM_SLEEP
e279b6c1
SR
1759 ---help---
1760 APM is a BIOS specification for saving power using several different
1761 techniques. This is mostly useful for battery powered laptops with
1762 APM compliant BIOSes. If you say Y here, the system time will be
1763 reset after a RESUME operation, the /proc/apm device will provide
1764 battery status information, and user-space programs will receive
1765 notification of APM "events" (e.g. battery status change).
1766
1767 If you select "Y" here, you can disable actual use of the APM
1768 BIOS by passing the "apm=off" option to the kernel at boot time.
1769
1770 Note that the APM support is almost completely disabled for
1771 machines with more than one CPU.
1772
1773 In order to use APM, you will need supporting software. For location
53471121 1774 and more information, read <file:Documentation/power/pm.txt> and the
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SR
1775 Battery Powered Linux mini-HOWTO, available from
1776 <http://www.tldp.org/docs.html#howto>.
1777
1778 This driver does not spin down disk drives (see the hdparm(8)
1779 manpage ("man 8 hdparm") for that), and it doesn't turn off
1780 VESA-compliant "green" monitors.
1781
1782 This driver does not support the TI 4000M TravelMate and the ACER
1783 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1784 desktop machines also don't have compliant BIOSes, and this driver
1785 may cause those machines to panic during the boot phase.
1786
1787 Generally, if you don't have a battery in your machine, there isn't
1788 much point in using this driver and you should say N. If you get
1789 random kernel OOPSes or reboots that don't seem to be related to
1790 anything, try disabling/enabling this option (or disabling/enabling
1791 APM in your BIOS).
1792
1793 Some other things you should try when experiencing seemingly random,
1794 "weird" problems:
1795
1796 1) make sure that you have enough swap space and that it is
1797 enabled.
1798 2) pass the "no-hlt" option to the kernel
1799 3) switch on floating point emulation in the kernel and pass
1800 the "no387" option to the kernel
1801 4) pass the "floppy=nodma" option to the kernel
1802 5) pass the "mem=4M" option to the kernel (thereby disabling
1803 all but the first 4 MB of RAM)
1804 6) make sure that the CPU is not over clocked.
1805 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1806 8) disable the cache from your BIOS settings
1807 9) install a fan for the video card or exchange video RAM
1808 10) install a better fan for the CPU
1809 11) exchange RAM chips
1810 12) exchange the motherboard.
1811
1812 To compile this driver as a module, choose M here: the
1813 module will be called apm.
1814
1815if APM
1816
1817config APM_IGNORE_USER_SUSPEND
1818 bool "Ignore USER SUSPEND"
8f9ca475 1819 ---help---
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SR
1820 This option will ignore USER SUSPEND requests. On machines with a
1821 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1822 series notebooks, it is necessary to say Y because of a BIOS bug.
1823
1824config APM_DO_ENABLE
1825 bool "Enable PM at boot time"
1826 ---help---
1827 Enable APM features at boot time. From page 36 of the APM BIOS
1828 specification: "When disabled, the APM BIOS does not automatically
1829 power manage devices, enter the Standby State, enter the Suspend
1830 State, or take power saving steps in response to CPU Idle calls."
1831 This driver will make CPU Idle calls when Linux is idle (unless this
1832 feature is turned off -- see "Do CPU IDLE calls", below). This
1833 should always save battery power, but more complicated APM features
1834 will be dependent on your BIOS implementation. You may need to turn
1835 this option off if your computer hangs at boot time when using APM
1836 support, or if it beeps continuously instead of suspending. Turn
1837 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1838 T400CDT. This is off by default since most machines do fine without
1839 this feature.
1840
1841config APM_CPU_IDLE
1842 bool "Make CPU Idle calls when idle"
8f9ca475 1843 ---help---
e279b6c1
SR
1844 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1845 On some machines, this can activate improved power savings, such as
1846 a slowed CPU clock rate, when the machine is idle. These idle calls
1847 are made after the idle loop has run for some length of time (e.g.,
1848 333 mS). On some machines, this will cause a hang at boot time or
1849 whenever the CPU becomes idle. (On machines with more than one CPU,
1850 this option does nothing.)
1851
1852config APM_DISPLAY_BLANK
1853 bool "Enable console blanking using APM"
8f9ca475 1854 ---help---
e279b6c1
SR
1855 Enable console blanking using the APM. Some laptops can use this to
1856 turn off the LCD backlight when the screen blanker of the Linux
1857 virtual console blanks the screen. Note that this is only used by
1858 the virtual console screen blanker, and won't turn off the backlight
1859 when using the X Window system. This also doesn't have anything to
1860 do with your VESA-compliant power-saving monitor. Further, this
1861 option doesn't work for all laptops -- it might not turn off your
1862 backlight at all, or it might print a lot of errors to the console,
1863 especially if you are using gpm.
1864
1865config APM_ALLOW_INTS
1866 bool "Allow interrupts during APM BIOS calls"
8f9ca475 1867 ---help---
e279b6c1
SR
1868 Normally we disable external interrupts while we are making calls to
1869 the APM BIOS as a measure to lessen the effects of a badly behaving
1870 BIOS implementation. The BIOS should reenable interrupts if it
1871 needs to. Unfortunately, some BIOSes do not -- especially those in
1872 many of the newer IBM Thinkpads. If you experience hangs when you
1873 suspend, try setting this to Y. Otherwise, say N.
1874
e279b6c1
SR
1875endif # APM
1876
1877source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1878
1879source "drivers/cpuidle/Kconfig"
1880
27471fdb
AH
1881source "drivers/idle/Kconfig"
1882
e279b6c1
SR
1883endmenu
1884
1885
1886menu "Bus options (PCI etc.)"
1887
1888config PCI
1ac97018 1889 bool "PCI support"
1c858087 1890 default y
e279b6c1 1891 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
8f9ca475 1892 ---help---
e279b6c1
SR
1893 Find out whether you have a PCI motherboard. PCI is the name of a
1894 bus system, i.e. the way the CPU talks to the other stuff inside
1895 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1896 VESA. If you have PCI, say Y, otherwise N.
1897
e279b6c1
SR
1898choice
1899 prompt "PCI access mode"
efefa6f6 1900 depends on X86_32 && PCI
e279b6c1
SR
1901 default PCI_GOANY
1902 ---help---
1903 On PCI systems, the BIOS can be used to detect the PCI devices and
1904 determine their configuration. However, some old PCI motherboards
1905 have BIOS bugs and may crash if this is done. Also, some embedded
1906 PCI-based systems don't have any BIOS at all. Linux can also try to
1907 detect the PCI hardware directly without using the BIOS.
1908
1909 With this option, you can specify how Linux should detect the
1910 PCI devices. If you choose "BIOS", the BIOS will be used,
1911 if you choose "Direct", the BIOS won't be used, and if you
1912 choose "MMConfig", then PCI Express MMCONFIG will be used.
1913 If you choose "Any", the kernel will try MMCONFIG, then the
1914 direct access method and falls back to the BIOS if that doesn't
1915 work. If unsure, go with the default, which is "Any".
1916
1917config PCI_GOBIOS
1918 bool "BIOS"
1919
1920config PCI_GOMMCONFIG
1921 bool "MMConfig"
1922
1923config PCI_GODIRECT
1924 bool "Direct"
1925
3ef0e1f8
AS
1926config PCI_GOOLPC
1927 bool "OLPC"
1928 depends on OLPC
1929
2bdd1b03
AS
1930config PCI_GOANY
1931 bool "Any"
1932
e279b6c1
SR
1933endchoice
1934
1935config PCI_BIOS
3c2362e6 1936 def_bool y
efefa6f6 1937 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
1938
1939# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1940config PCI_DIRECT
3c2362e6 1941 def_bool y
efefa6f6 1942 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
e279b6c1
SR
1943
1944config PCI_MMCONFIG
3c2362e6 1945 def_bool y
5f0db7a2 1946 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 1947
3ef0e1f8 1948config PCI_OLPC
2bdd1b03
AS
1949 def_bool y
1950 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 1951
e279b6c1 1952config PCI_DOMAINS
3c2362e6 1953 def_bool y
e279b6c1 1954 depends on PCI
e279b6c1
SR
1955
1956config PCI_MMCONFIG
1957 bool "Support mmconfig PCI config space access"
1958 depends on X86_64 && PCI && ACPI
1959
3f6ea84a
IS
1960config PCI_CNB20LE_QUIRK
1961 bool "Read CNB20LE Host Bridge Windows"
1962 depends on PCI
1963 help
1964 Read the PCI windows out of the CNB20LE host bridge. This allows
1965 PCI hotplug to work on systems with the CNB20LE chipset which do
1966 not have ACPI.
1967
e279b6c1
SR
1968config DMAR
1969 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
4cf2e75d 1970 depends on PCI_MSI && ACPI && EXPERIMENTAL
e279b6c1
SR
1971 help
1972 DMA remapping (DMAR) devices support enables independent address
1973 translations for Direct Memory Access (DMA) from devices.
1974 These DMA remapping devices are reported via ACPI tables
1975 and include PCI device scope covered by these DMA
1976 remapping devices.
1977
0cd5c3c8 1978config DMAR_DEFAULT_ON
f6be37fd 1979 def_bool y
0cd5c3c8
KM
1980 prompt "Enable DMA Remapping Devices by default"
1981 depends on DMAR
1982 help
1983 Selecting this option will enable a DMAR device at boot time if
1984 one is found. If this option is not selected, DMAR support can
1985 be enabled by passing intel_iommu=on to the kernel. It is
1986 recommended you say N here while the DMAR code remains
1987 experimental.
1988
62edf5dc 1989config DMAR_BROKEN_GFX_WA
6fc108a0 1990 bool "Workaround broken graphics drivers (going away soon)"
0c02a20f 1991 depends on DMAR && BROKEN
62edf5dc
DW
1992 ---help---
1993 Current Graphics drivers tend to use physical address
1994 for DMA and avoid using DMA APIs. Setting this config
1995 option permits the IOMMU driver to set a unity map for
1996 all the OS-visible memory. Hence the driver can continue
1997 to use physical addresses for DMA, at least until this
1998 option is removed in the 2.6.32 kernel.
1999
e279b6c1 2000config DMAR_FLOPPY_WA
3c2362e6 2001 def_bool y
e279b6c1 2002 depends on DMAR
8f9ca475 2003 ---help---
c7ab48d2 2004 Floppy disk drivers are known to bypass DMA API calls
8f9ca475
IM
2005 thereby failing to work when IOMMU is enabled. This
2006 workaround will setup a 1:1 mapping for the first
c7ab48d2 2007 16MiB to make floppy (an ISA device) work.
e279b6c1 2008
9fa8c481
SS
2009config INTR_REMAP
2010 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
2011 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
8f9ca475
IM
2012 ---help---
2013 Supports Interrupt remapping for IO-APIC and MSI devices.
2014 To use x2apic mode in the CPU's which support x2APIC enhancements or
2015 to support platforms with CPU's having > 8 bit APIC ID, say Y.
9fa8c481 2016
e279b6c1
SR
2017source "drivers/pci/pcie/Kconfig"
2018
2019source "drivers/pci/Kconfig"
2020
2021# x86_64 have no ISA slots, but do have ISA-style DMA.
2022config ISA_DMA_API
3c2362e6 2023 def_bool y
e279b6c1
SR
2024
2025if X86_32
2026
2027config ISA
2028 bool "ISA support"
8f9ca475 2029 ---help---
e279b6c1
SR
2030 Find out whether you have ISA slots on your motherboard. ISA is the
2031 name of a bus system, i.e. the way the CPU talks to the other stuff
2032 inside your box. Other bus systems are PCI, EISA, MicroChannel
2033 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2034 newer boards don't support it. If you have ISA, say Y, otherwise N.
2035
2036config EISA
2037 bool "EISA support"
2038 depends on ISA
2039 ---help---
2040 The Extended Industry Standard Architecture (EISA) bus was
2041 developed as an open alternative to the IBM MicroChannel bus.
2042
2043 The EISA bus provided some of the features of the IBM MicroChannel
2044 bus while maintaining backward compatibility with cards made for
2045 the older ISA bus. The EISA bus saw limited use between 1988 and
2046 1995 when it was made obsolete by the PCI bus.
2047
2048 Say Y here if you are building a kernel for an EISA-based machine.
2049
2050 Otherwise, say N.
2051
2052source "drivers/eisa/Kconfig"
2053
2054config MCA
72ee6ebb 2055 bool "MCA support"
8f9ca475 2056 ---help---
e279b6c1
SR
2057 MicroChannel Architecture is found in some IBM PS/2 machines and
2058 laptops. It is a bus system similar to PCI or ISA. See
2059 <file:Documentation/mca.txt> (and especially the web page given
2060 there) before attempting to build an MCA bus kernel.
2061
2062source "drivers/mca/Kconfig"
2063
2064config SCx200
2065 tristate "NatSemi SCx200 support"
8f9ca475 2066 ---help---
e279b6c1
SR
2067 This provides basic support for National Semiconductor's
2068 (now AMD's) Geode processors. The driver probes for the
2069 PCI-IDs of several on-chip devices, so its a good dependency
2070 for other scx200_* drivers.
2071
2072 If compiled as a module, the driver is named scx200.
2073
2074config SCx200HR_TIMER
2075 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2076 depends on SCx200
e279b6c1 2077 default y
8f9ca475 2078 ---help---
e279b6c1
SR
2079 This driver provides a clocksource built upon the on-chip
2080 27MHz high-resolution timer. Its also a workaround for
2081 NSC Geode SC-1100's buggy TSC, which loses time when the
2082 processor goes idle (as is done by the scheduler). The
2083 other workaround is idle=poll boot option.
2084
3ef0e1f8
AS
2085config OLPC
2086 bool "One Laptop Per Child support"
3c554946 2087 select GPIOLIB
8f9ca475 2088 ---help---
3ef0e1f8
AS
2089 Add support for detecting the unique features of the OLPC
2090 XO hardware.
2091
fd699c76
AS
2092config OLPC_OPENFIRMWARE
2093 bool "Support for OLPC's Open Firmware"
2094 depends on !X86_64 && !X86_PAE
2095 default y if OLPC
2096 help
2097 This option adds support for the implementation of Open Firmware
2098 that is used on the OLPC XO-1 Children's Machine.
2099 If unsure, say N here.
2100
bc0120fd
SR
2101endif # X86_32
2102
23ac4ae8 2103config AMD_NB
e279b6c1 2104 def_bool y
0e152cd7 2105 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2106
2107source "drivers/pcmcia/Kconfig"
2108
2109source "drivers/pci/hotplug/Kconfig"
2110
2111endmenu
2112
2113
2114menu "Executable file formats / Emulations"
2115
2116source "fs/Kconfig.binfmt"
2117
2118config IA32_EMULATION
2119 bool "IA32 Emulation"
2120 depends on X86_64
a97f52e6 2121 select COMPAT_BINFMT_ELF
8f9ca475 2122 ---help---
e279b6c1
SR
2123 Include code to run 32-bit programs under a 64-bit kernel. You should
2124 likely turn this on, unless you're 100% sure that you don't have any
2125 32-bit programs left.
2126
2127config IA32_AOUT
8f9ca475
IM
2128 tristate "IA32 a.out support"
2129 depends on IA32_EMULATION
2130 ---help---
2131 Support old a.out binaries in the 32bit emulation.
e279b6c1
SR
2132
2133config COMPAT
3c2362e6 2134 def_bool y
e279b6c1 2135 depends on IA32_EMULATION
e279b6c1
SR
2136
2137config COMPAT_FOR_U64_ALIGNMENT
2138 def_bool COMPAT
2139 depends on X86_64
2140
2141config SYSVIPC_COMPAT
3c2362e6 2142 def_bool y
b8992195 2143 depends on COMPAT && SYSVIPC
e279b6c1
SR
2144
2145endmenu
2146
2147
e5beae16
KP
2148config HAVE_ATOMIC_IOMAP
2149 def_bool y
2150 depends on X86_32
2151
3cba11d3
MH
2152config HAVE_TEXT_POKE_SMP
2153 bool
2154 select STOP_MACHINE if SMP
2155
e279b6c1
SR
2156source "net/Kconfig"
2157
2158source "drivers/Kconfig"
2159
2160source "drivers/firmware/Kconfig"
2161
2162source "fs/Kconfig"
2163
e279b6c1
SR
2164source "arch/x86/Kconfig.debug"
2165
2166source "security/Kconfig"
2167
2168source "crypto/Kconfig"
2169
edf88417
AK
2170source "arch/x86/kvm/Kconfig"
2171
e279b6c1 2172source "lib/Kconfig"