x86: Remove old bootmem code
[deliverable/linux.git] / arch / x86 / Kconfig
CommitLineData
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)
28b2ee20 28 select HAVE_IOREMAP_PROT
3f550096 29 select HAVE_KPROBES
72d7c3b3 30 select HAVE_MEMBLOCK
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
677aa9f7 37 select HAVE_DYNAMIC_FTRACE
606576ce 38 select HAVE_FUNCTION_TRACER
48d68b20 39 select HAVE_FUNCTION_GRAPH_TRACER
71e308a2 40 select HAVE_FUNCTION_GRAPH_FP_TEST
60a7ecf4 41 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
9a5fd902 42 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
66700001 43 select HAVE_SYSCALL_TRACEPOINTS
e0ec9483 44 select HAVE_KVM
49793b03 45 select HAVE_ARCH_KGDB
99bbc4b1 46 select HAVE_ARCH_TRACEHOOK
323ec001 47 select HAVE_GENERIC_DMA_COHERENT if X86_32
58340a07 48 select HAVE_EFFICIENT_UNALIGNED_ACCESS
8d26487f 49 select USER_STACKTRACE_SUPPORT
f850c30c 50 select HAVE_REGS_AND_STACK_ACCESS_API
2118d0c5 51 select HAVE_DMA_API_DEBUG
2e9f3bdd
PA
52 select HAVE_KERNEL_GZIP
53 select HAVE_KERNEL_BZIP2
54 select HAVE_KERNEL_LZMA
13510997 55 select HAVE_KERNEL_LZO
0067f129 56 select HAVE_HW_BREAKPOINT
0102752e 57 select HAVE_MIXED_BREAKPOINTS_REGS
99e8c5a3
FW
58 select PERF_EVENTS
59 select ANON_INODES
0a4af3b0 60 select HAVE_ARCH_KMEMCHECK
7c68af6e 61 select HAVE_USER_RETURN_NOTIFIER
7d8330a5 62
ba7e4d13
IM
63config INSTRUCTION_DECODER
64 def_bool (KPROBES || PERF_EVENTS)
65
51b26ada
LT
66config OUTPUT_FORMAT
67 string
68 default "elf32-i386" if X86_32
69 default "elf64-x86-64" if X86_64
70
73531905 71config ARCH_DEFCONFIG
b9b39bfb 72 string
73531905
SR
73 default "arch/x86/configs/i386_defconfig" if X86_32
74 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 75
8d5fffb9 76config GENERIC_TIME
3c2362e6 77 def_bool y
8d5fffb9
SR
78
79config GENERIC_CMOS_UPDATE
3c2362e6 80 def_bool y
8d5fffb9
SR
81
82config CLOCKSOURCE_WATCHDOG
3c2362e6 83 def_bool y
8d5fffb9
SR
84
85config GENERIC_CLOCKEVENTS
3c2362e6 86 def_bool y
8d5fffb9
SR
87
88config GENERIC_CLOCKEVENTS_BROADCAST
3c2362e6 89 def_bool y
8d5fffb9
SR
90 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
91
92config LOCKDEP_SUPPORT
3c2362e6 93 def_bool y
8d5fffb9
SR
94
95config STACKTRACE_SUPPORT
3c2362e6 96 def_bool y
8d5fffb9 97
aa7d9350
HC
98config HAVE_LATENCYTOP_SUPPORT
99 def_bool y
100
8d5fffb9 101config MMU
3c2362e6 102 def_bool y
8d5fffb9
SR
103
104config ZONE_DMA
3c2362e6 105 def_bool y
8d5fffb9 106
8d5fffb9
SR
107config SBUS
108 bool
109
3bc4e459
FT
110config NEED_DMA_MAP_STATE
111 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
112
18e98307 113config NEED_SG_DMA_LENGTH
4a14d84e 114 def_bool y
18e98307 115
8d5fffb9 116config GENERIC_ISA_DMA
3c2362e6 117 def_bool y
8d5fffb9
SR
118
119config GENERIC_IOMAP
3c2362e6 120 def_bool y
8d5fffb9
SR
121
122config GENERIC_BUG
3c2362e6 123 def_bool y
8d5fffb9 124 depends on BUG
b93a531e
JB
125 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
126
127config GENERIC_BUG_RELATIVE_POINTERS
128 bool
8d5fffb9
SR
129
130config GENERIC_HWEIGHT
3c2362e6 131 def_bool y
8d5fffb9 132
a6082959 133config GENERIC_GPIO
9ba16087 134 bool
a6082959 135
8d5fffb9 136config ARCH_MAY_HAVE_PC_FDC
3c2362e6 137 def_bool y
8d5fffb9 138
1032c0ba
SR
139config RWSEM_GENERIC_SPINLOCK
140 def_bool !X86_XADD
141
142config RWSEM_XCHGADD_ALGORITHM
143 def_bool X86_XADD
144
a6869cc4
VP
145config ARCH_HAS_CPU_IDLE_WAIT
146 def_bool y
147
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SR
148config GENERIC_CALIBRATE_DELAY
149 def_bool y
150
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SR
151config GENERIC_TIME_VSYSCALL
152 bool
153 default X86_64
154
9a0b8415 155config ARCH_HAS_CPU_RELAX
156 def_bool y
157
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VP
158config ARCH_HAS_DEFAULT_IDLE
159 def_bool y
160
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PE
161config ARCH_HAS_CACHE_LINE_SIZE
162 def_bool y
163
dd5af90a 164config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 165 def_bool y
b32ef636 166
08fc4580
TH
167config NEED_PER_CPU_EMBED_FIRST_CHUNK
168 def_bool y
169
170config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
171 def_bool y
172
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MT
173config HAVE_CPUMASK_OF_CPU_MAP
174 def_bool X86_64_SMP
175
801e4062
JB
176config ARCH_HIBERNATION_POSSIBLE
177 def_bool y
801e4062 178
f4cb5700
JB
179config ARCH_SUSPEND_POSSIBLE
180 def_bool y
f4cb5700 181
8d5fffb9
SR
182config ZONE_DMA32
183 bool
184 default X86_64
185
186config ARCH_POPULATES_NODE_MAP
187 def_bool y
188
189config AUDIT_ARCH
190 bool
191 default X86_64
192
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IM
193config ARCH_SUPPORTS_OPTIMIZED_INLINING
194 def_bool y
195
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AM
196config ARCH_SUPPORTS_DEBUG_PAGEALLOC
197 def_bool y
198
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SW
199config HAVE_INTEL_TXT
200 def_bool y
201 depends on EXPERIMENTAL && DMAR && ACPI
202
8d5fffb9
SR
203# Use the generic interrupt handling code in kernel/irq/:
204config GENERIC_HARDIRQS
6fc108a0 205 def_bool y
8d5fffb9 206
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TG
207config GENERIC_HARDIRQS_NO__DO_IRQ
208 def_bool y
209
8d5fffb9 210config GENERIC_IRQ_PROBE
6fc108a0 211 def_bool y
8d5fffb9
SR
212
213config GENERIC_PENDING_IRQ
6fc108a0 214 def_bool y
8d5fffb9 215 depends on GENERIC_HARDIRQS && SMP
8d5fffb9 216
6cd10f8d
JB
217config USE_GENERIC_SMP_HELPERS
218 def_bool y
219 depends on SMP
220
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SR
221config X86_32_SMP
222 def_bool y
223 depends on X86_32 && SMP
224
225config X86_64_SMP
226 def_bool y
227 depends on X86_64 && SMP
228
8d5fffb9 229config X86_HT
6fc108a0 230 def_bool y
ee0011a7 231 depends on SMP
8d5fffb9
SR
232
233config X86_TRAMPOLINE
6fc108a0 234 def_bool y
3e5095d1 235 depends on SMP || (64BIT && ACPI_SLEEP)
8d5fffb9 236
ccbeed3a
TH
237config X86_32_LAZY_GS
238 def_bool y
60a5317f 239 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 240
d61931d8
BP
241config ARCH_HWEIGHT_CFLAGS
242 string
243 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
244 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
245
8d5fffb9
SR
246config KTIME_SCALAR
247 def_bool X86_32
506f1d07 248source "init/Kconfig"
dc52ddc0 249source "kernel/Kconfig.freezer"
8d5fffb9 250
506f1d07
SR
251menu "Processor type and features"
252
253source "kernel/time/Kconfig"
254
255config SMP
256 bool "Symmetric multi-processing support"
257 ---help---
258 This enables support for systems with more than one CPU. If you have
259 a system with only one CPU, like most personal computers, say N. If
260 you have a system with more than one CPU, say Y.
261
262 If you say N here, the kernel will run on single and multiprocessor
263 machines, but will use only one CPU of a multiprocessor machine. If
264 you say Y here, the kernel will run on many, but not all,
265 singleprocessor machines. On a singleprocessor machine, the kernel
266 will run faster if you say N here.
267
268 Note that if you say Y here and choose architecture "586" or
269 "Pentium" under "Processor family", the kernel will not work on 486
270 architectures. Similarly, multiprocessor kernels for the "PPro"
271 architecture may not work on all Pentium based boards.
272
273 People using multiprocessor machines who say Y here should also say
274 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
275 Management" code will be disabled if you say Y here.
276
03502faa 277 See also <file:Documentation/i386/IO-APIC.txt>,
506f1d07
SR
278 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
279 <http://www.tldp.org/docs.html#howto>.
280
281 If you don't know what to do here, say N.
282
06cd9a7d
YL
283config X86_X2APIC
284 bool "Support x2apic"
f7d7f866 285 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
06cd9a7d
YL
286 ---help---
287 This enables x2apic support on CPUs that have this feature.
288
289 This allows 32-bit apic IDs (so it can support very large systems),
290 and accesses the local apic via MSRs not via mmio.
291
06cd9a7d
YL
292 If you don't know what to do here, say N.
293
0b8f1efa
YL
294config SPARSE_IRQ
295 bool "Support sparse irq numbering"
17483a1f 296 depends on PCI_MSI || HT_IRQ
8f9ca475 297 ---help---
973656fe
IM
298 This enables support for sparse irqs. This is useful for distro
299 kernels that want to define a high CONFIG_NR_CPUS value but still
300 want to have low kernel memory footprint on smaller machines.
0b8f1efa 301
973656fe
IM
302 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
303 out the irq_desc[] array in a more NUMA-friendly way. )
304
305 If you don't know what to do here, say N.
0b8f1efa 306
15e957d0
YL
307config NUMA_IRQ_DESC
308 def_bool y
b9098957 309 depends on SPARSE_IRQ && NUMA
48a1b10a 310
6695c85b 311config X86_MPPARSE
7a527688
JB
312 bool "Enable MPS table" if ACPI
313 default y
5ab74722 314 depends on X86_LOCAL_APIC
8f9ca475 315 ---help---
6695c85b
YL
316 For old smp systems that do not have proper acpi support. Newer systems
317 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 318
26f7ef14
YL
319config X86_BIGSMP
320 bool "Support for big SMP systems with more than 8 CPUs"
321 depends on X86_32 && SMP
8f9ca475 322 ---help---
26f7ef14 323 This option is needed for the systems that have more than 8 CPUs
506f1d07 324
8425091f 325if X86_32
c5c606d9
RT
326config X86_EXTENDED_PLATFORM
327 bool "Support for extended (non-PC) x86 platforms"
328 default y
8f9ca475 329 ---help---
06ac8346
IM
330 If you disable this option then the kernel will only support
331 standard PC platforms. (which covers the vast majority of
332 systems out there.)
333
8425091f
RT
334 If you enable this option then you'll be able to select support
335 for the following (non-PC) 32 bit x86 platforms:
336 AMD Elan
337 NUMAQ (IBM/Sequent)
338 RDC R-321x SoC
339 SGI 320/540 (Visual Workstation)
340 Summit/EXA (IBM x440)
341 Unisys ES7000 IA32 series
3f4110a4 342 Moorestown MID devices
06ac8346
IM
343
344 If you have one of these systems, or if you want to build a
345 generic distribution kernel, say Y here - otherwise say N.
8425091f 346endif
06ac8346 347
8425091f
RT
348if X86_64
349config X86_EXTENDED_PLATFORM
350 bool "Support for extended (non-PC) x86 platforms"
351 default y
352 ---help---
353 If you disable this option then the kernel will only support
354 standard PC platforms. (which covers the vast majority of
355 systems out there.)
356
357 If you enable this option then you'll be able to select support
358 for the following (non-PC) 64 bit x86 platforms:
359 ScaleMP vSMP
360 SGI Ultraviolet
361
362 If you have one of these systems, or if you want to build a
363 generic distribution kernel, say Y here - otherwise say N.
364endif
c5c606d9
RT
365# This is an alphabetically sorted list of 64 bit extended platforms
366# Please maintain the alphabetic order if and when there are additions
506f1d07 367
c5c606d9
RT
368config X86_VSMP
369 bool "ScaleMP vSMP"
370 select PARAVIRT
371 depends on X86_64 && PCI
372 depends on X86_EXTENDED_PLATFORM
8f9ca475 373 ---help---
c5c606d9
RT
374 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
375 supposed to run on these EM64T-based machines. Only choose this option
376 if you have one of these machines.
5e3a77e9 377
03b48632
NP
378config X86_UV
379 bool "SGI Ultraviolet"
380 depends on X86_64
c5c606d9 381 depends on X86_EXTENDED_PLATFORM
54c28d29 382 depends on NUMA
9d6c26e7 383 depends on X86_X2APIC
8f9ca475 384 ---help---
03b48632
NP
385 This option is needed in order to support SGI Ultraviolet systems.
386 If you don't have one of these, you should say N here.
387
c5c606d9
RT
388# Following is an alphabetically sorted list of 32 bit extended platforms
389# Please maintain the alphabetic order if and when there are additions
506f1d07
SR
390
391config X86_ELAN
392 bool "AMD Elan"
393 depends on X86_32
c5c606d9 394 depends on X86_EXTENDED_PLATFORM
8f9ca475 395 ---help---
506f1d07
SR
396 Select this for an AMD Elan processor.
397
398 Do not use this option for K6/Athlon/Opteron processors!
399
400 If unsure, choose "PC-compatible" instead.
401
3f4110a4
TG
402config X86_MRST
403 bool "Moorestown MID platform"
4b2f3f7d
JP
404 depends on PCI
405 depends on PCI_GOANY
3f4110a4
TG
406 depends on X86_32
407 depends on X86_EXTENDED_PLATFORM
4b2f3f7d 408 depends on X86_IO_APIC
bb24c471 409 select APB_TIMER
3f4110a4
TG
410 ---help---
411 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
412 Internet Device(MID) platform. Moorestown consists of two chips:
413 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
414 Unlike standard x86 PCs, Moorestown does not have many legacy devices
415 nor standard legacy replacement devices/features. e.g. Moorestown does
416 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
417
c5c606d9
RT
418config X86_RDC321X
419 bool "RDC R-321x SoC"
506f1d07 420 depends on X86_32
c5c606d9
RT
421 depends on X86_EXTENDED_PLATFORM
422 select M486
423 select X86_REBOOTFIXUPS
424 ---help---
425 This option is needed for RDC R-321x system-on-chip, also known
426 as R-8610-(G).
427 If you don't have one of these chips, you should say N here.
428
e0c7ae37 429config X86_32_NON_STANDARD
9c398017
IM
430 bool "Support non-standard 32-bit SMP architectures"
431 depends on X86_32 && SMP
c5c606d9 432 depends on X86_EXTENDED_PLATFORM
8f9ca475
IM
433 ---help---
434 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
d49c4288
YL
435 subarchitectures. It is intended for a generic binary kernel.
436 if you select them all, kernel will probe it one by one. and will
437 fallback to default.
438
c5c606d9 439# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 440
506f1d07
SR
441config X86_NUMAQ
442 bool "NUMAQ (IBM/Sequent)"
e0c7ae37 443 depends on X86_32_NON_STANDARD
a92d152e 444 depends on PCI
506f1d07 445 select NUMA
9c398017 446 select X86_MPPARSE
8f9ca475 447 ---help---
d49c4288
YL
448 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
449 NUMA multiquad box. This changes the way that processors are
450 bootstrapped, and uses Clustered Logical APIC addressing mode instead
451 of Flat Logical. You will need a new lynxer.elf file to flash your
452 firmware with - send email to <Martin.Bligh@us.ibm.com>.
506f1d07 453
d949f36f 454config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 455 def_bool y
d949f36f
LT
456 # MCE code calls memory_failure():
457 depends on X86_MCE
458 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
459 depends on !X86_NUMAQ
460 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
461 depends on X86_64 || !SPARSEMEM
462 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 463
1b84e1c8
IM
464config X86_VISWS
465 bool "SGI 320/540 (Visual Workstation)"
c5c606d9
RT
466 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
467 depends on X86_32_NON_STANDARD
468 ---help---
1b84e1c8
IM
469 The SGI Visual Workstation series is an IA32-based workstation
470 based on SGI systems chips with some legacy PC hardware attached.
471
472 Say Y here to create a kernel to run on the SGI 320 or 540.
473
474 A kernel compiled for the Visual Workstation will run on general
475 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
476
9c398017
IM
477config X86_SUMMIT
478 bool "Summit/EXA (IBM x440)"
e0c7ae37 479 depends on X86_32_NON_STANDARD
8f9ca475 480 ---help---
9c398017
IM
481 This option is needed for IBM systems that use the Summit/EXA chipset.
482 In particular, it is needed for the x440.
1f972768 483
9c398017 484config X86_ES7000
c5c606d9 485 bool "Unisys ES7000 IA32 series"
26f7ef14 486 depends on X86_32_NON_STANDARD && X86_BIGSMP
8f9ca475 487 ---help---
9c398017
IM
488 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
489 supposed to run on an IA32-based Unisys ES7000 system.
490
ae1e9130 491config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
492 def_bool y
493 prompt "Single-depth WCHAN output"
a87d0914 494 depends on X86
8f9ca475 495 ---help---
506f1d07
SR
496 Calculate simpler /proc/<PID>/wchan values. If this option
497 is disabled then wchan values will recurse back to the
498 caller function. This provides more accurate wchan values,
499 at the expense of slightly more scheduling overhead.
500
501 If in doubt, say "Y".
502
506f1d07
SR
503menuconfig PARAVIRT_GUEST
504 bool "Paravirtualized guest support"
8f9ca475 505 ---help---
506f1d07
SR
506 Say Y here to get to see options related to running Linux under
507 various hypervisors. This option alone does not add any kernel code.
508
509 If you say N, all options in this submenu will be skipped and disabled.
510
511if PARAVIRT_GUEST
512
513source "arch/x86/xen/Kconfig"
514
515config VMI
d0153ca3 516 bool "VMI Guest support (DEPRECATED)"
506f1d07 517 select PARAVIRT
42d545c9 518 depends on X86_32
8f9ca475 519 ---help---
506f1d07
SR
520 VMI provides a paravirtualized interface to the VMware ESX server
521 (it could be used by other hypervisors in theory too, but is not
522 at the moment), by linking the kernel to a GPL-ed ROM module
523 provided by the hypervisor.
524
d0153ca3
AK
525 As of September 2009, VMware has started a phased retirement
526 of this feature from VMware's products. Please see
527 feature-removal-schedule.txt for details. If you are
528 planning to enable this option, please note that you cannot
529 live migrate a VMI enabled VM to a future VMware product,
530 which doesn't support VMI. So if you expect your kernel to
531 seamlessly migrate to newer VMware products, keep this
532 disabled.
533
790c73f6
GOC
534config KVM_CLOCK
535 bool "KVM paravirtualized clock"
536 select PARAVIRT
f6e16d5a 537 select PARAVIRT_CLOCK
8f9ca475 538 ---help---
790c73f6
GOC
539 Turning on this option will allow you to run a paravirtualized clock
540 when running over the KVM hypervisor. Instead of relying on a PIT
541 (or probably other) emulation by the underlying device model, the host
542 provides the guest with timing infrastructure such as time of day, and
543 system time
544
0cf1bfd2
MT
545config KVM_GUEST
546 bool "KVM Guest support"
547 select PARAVIRT
8f9ca475
IM
548 ---help---
549 This option enables various optimizations for running under the KVM
550 hypervisor.
0cf1bfd2 551
506f1d07
SR
552source "arch/x86/lguest/Kconfig"
553
e61bd94a
EPH
554config PARAVIRT
555 bool "Enable paravirtualization code"
8f9ca475 556 ---help---
e61bd94a
EPH
557 This changes the kernel so it can modify itself when it is run
558 under a hypervisor, potentially improving performance significantly
559 over full virtualization. However, when run without a hypervisor
560 the kernel is theoretically slower and slightly larger.
561
b4ecc126
JF
562config PARAVIRT_SPINLOCKS
563 bool "Paravirtualization layer for spinlocks"
564 depends on PARAVIRT && SMP && EXPERIMENTAL
565 ---help---
566 Paravirtualized spinlocks allow a pvops backend to replace the
567 spinlock implementation with something virtualization-friendly
568 (for example, block the virtual CPU rather than spinning).
569
570 Unfortunately the downside is an up to 5% performance hit on
571 native kernels, with various workloads.
572
573 If you are unsure how to answer this question, answer N.
574
7af192c9
GH
575config PARAVIRT_CLOCK
576 bool
7af192c9 577
506f1d07
SR
578endif
579
97349135 580config PARAVIRT_DEBUG
8f9ca475
IM
581 bool "paravirt-ops debugging"
582 depends on PARAVIRT && DEBUG_KERNEL
583 ---help---
584 Enable to debug paravirt_ops internals. Specifically, BUG if
585 a paravirt_op is missing when it is called.
97349135 586
08677214 587config NO_BOOTMEM
774ea0bc 588 def_bool y
08677214 589
03273184
YL
590config MEMTEST
591 bool "Memtest"
8f9ca475 592 ---help---
c64df707 593 This option adds a kernel parameter 'memtest', which allows memtest
03273184 594 to be set.
8f9ca475
IM
595 memtest=0, mean disabled; -- default
596 memtest=1, mean do 1 test pattern;
597 ...
598 memtest=4, mean do 4 test patterns.
aba3728c 599 If you are unsure how to answer this question, answer N.
506f1d07
SR
600
601config X86_SUMMIT_NUMA
3c2362e6 602 def_bool y
e0c7ae37 603 depends on X86_32 && NUMA && X86_32_NON_STANDARD
506f1d07
SR
604
605config X86_CYCLONE_TIMER
3c2362e6 606 def_bool y
e0c7ae37 607 depends on X86_32_NON_STANDARD
506f1d07 608
506f1d07
SR
609source "arch/x86/Kconfig.cpu"
610
611config HPET_TIMER
3c2362e6 612 def_bool X86_64
506f1d07 613 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
614 ---help---
615 Use the IA-PC HPET (High Precision Event Timer) to manage
616 time in preference to the PIT and RTC, if a HPET is
617 present.
618 HPET is the next generation timer replacing legacy 8254s.
619 The HPET provides a stable time base on SMP
620 systems, unlike the TSC, but it is more expensive to access,
621 as it is off-chip. You can find the HPET spec at
622 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
506f1d07 623
8f9ca475
IM
624 You can safely choose Y here. However, HPET will only be
625 activated if the platform and the BIOS support this feature.
626 Otherwise the 8254 will be used for timing services.
506f1d07 627
8f9ca475 628 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
629
630config HPET_EMULATE_RTC
3c2362e6 631 def_bool y
9d8af78b 632 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 633
bb24c471
JP
634config APB_TIMER
635 def_bool y if MRST
636 prompt "Langwell APB Timer Support" if X86_MRST
637 help
638 APB timer is the replacement for 8254, HPET on X86 MID platforms.
639 The APBT provides a stable time base on SMP
640 systems, unlike the TSC, but it is more expensive to access,
641 as it is off-chip. APB timers are always running regardless of CPU
642 C states, they are used as per CPU clockevent device when possible.
643
506f1d07
SR
644# Mark as embedded because too many people got it wrong.
645# The code disables itself when not needed.
7ae9392c
TP
646config DMI
647 default y
648 bool "Enable DMI scanning" if EMBEDDED
8f9ca475 649 ---help---
7ae9392c
TP
650 Enabled scanning of DMI to identify machine quirks. Say Y
651 here unless you have verified that your setup is not
652 affected by entries in the DMI blacklist. Required by PNP
653 BIOS code.
654
506f1d07
SR
655config GART_IOMMU
656 bool "GART IOMMU support" if EMBEDDED
657 default y
658 select SWIOTLB
0e152cd7 659 depends on X86_64 && PCI && K8_NB
8f9ca475 660 ---help---
506f1d07
SR
661 Support for full DMA access of devices with 32bit memory access only
662 on systems with more than 3GB. This is usually needed for USB,
663 sound, many IDE/SATA chipsets and some other devices.
664 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
665 based hardware IOMMU and a software bounce buffer based IOMMU used
666 on Intel systems and as fallback.
667 The code is only active when needed (enough memory and limited
668 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
669 too.
670
671config CALGARY_IOMMU
672 bool "IBM Calgary IOMMU support"
673 select SWIOTLB
674 depends on X86_64 && PCI && EXPERIMENTAL
8f9ca475 675 ---help---
506f1d07
SR
676 Support for hardware IOMMUs in IBM's xSeries x366 and x460
677 systems. Needed to run systems with more than 3GB of memory
678 properly with 32-bit PCI devices that do not support DAC
679 (Double Address Cycle). Calgary also supports bus level
680 isolation, where all DMAs pass through the IOMMU. This
681 prevents them from going anywhere except their intended
682 destination. This catches hard-to-find kernel bugs and
683 mis-behaving drivers and devices that do not use the DMA-API
684 properly to set up their DMA buffers. The IOMMU can be
685 turned off at boot time with the iommu=off parameter.
686 Normally the kernel will make the right choice by itself.
687 If unsure, say Y.
688
689config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
690 def_bool y
691 prompt "Should Calgary be enabled by default?"
506f1d07 692 depends on CALGARY_IOMMU
8f9ca475 693 ---help---
506f1d07
SR
694 Should Calgary be enabled by default? if you choose 'y', Calgary
695 will be used (if it exists). If you choose 'n', Calgary will not be
696 used even if it exists. If you choose 'n' and would like to use
697 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
698 If unsure, say Y.
699
2b188723
JR
700config AMD_IOMMU
701 bool "AMD IOMMU support"
07c40e8a 702 select SWIOTLB
a80dc3e0 703 select PCI_MSI
24d2ba0a 704 depends on X86_64 && PCI && ACPI
8f9ca475 705 ---help---
18d22200
JR
706 With this option you can enable support for AMD IOMMU hardware in
707 your system. An IOMMU is a hardware component which provides
708 remapping of DMA memory accesses from devices. With an AMD IOMMU you
709 can isolate the the DMA memory of different devices and protect the
710 system from misbehaving device drivers or hardware.
711
712 You can find out if your system has an AMD IOMMU if you look into
713 your BIOS for an option to enable it or if you have an IVRS ACPI
714 table.
2b188723 715
2e117604
JR
716config AMD_IOMMU_STATS
717 bool "Export AMD IOMMU statistics to debugfs"
718 depends on AMD_IOMMU
719 select DEBUG_FS
8f9ca475 720 ---help---
2e117604
JR
721 This option enables code in the AMD IOMMU driver to collect various
722 statistics about whats happening in the driver and exports that
723 information to userspace via debugfs.
724 If unsure, say N.
725
506f1d07
SR
726# need this always selected by IOMMU for the VIA workaround
727config SWIOTLB
a1afd01c 728 def_bool y if X86_64
8f9ca475 729 ---help---
506f1d07
SR
730 Support for software bounce buffers used on x86-64 systems
731 which don't have a hardware IOMMU (e.g. the current generation
732 of Intel's x86-64 CPUs). Using this PCI devices which can only
733 access 32-bits of memory can be used on systems with more than
734 3 GB of memory. If unsure, say Y.
735
a8522509 736config IOMMU_HELPER
18b743dc 737 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
d25e26b6 738
1aaf1183
JR
739config IOMMU_API
740 def_bool (AMD_IOMMU || DMAR)
741
1184dc2f
MT
742config MAXSMP
743 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
36f5101a
MT
744 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
745 select CPUMASK_OFFSTACK
8f9ca475 746 ---help---
1184dc2f
MT
747 Configure maximum number of CPUS and NUMA Nodes for this architecture.
748 If unsure, say N.
506f1d07
SR
749
750config NR_CPUS
36f5101a 751 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 752 range 2 8 if SMP && X86_32 && !X86_BIGSMP
36f5101a 753 range 2 512 if SMP && !MAXSMP
78637a97 754 default "1" if !SMP
d25e26b6 755 default "4096" if MAXSMP
78637a97
MT
756 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
757 default "8" if SMP
8f9ca475 758 ---help---
506f1d07 759 This allows you to specify the maximum number of CPUs which this
d25e26b6 760 kernel will support. The maximum supported value is 512 and the
506f1d07
SR
761 minimum value which makes sense is 2.
762
763 This is purely to save memory - each supported CPU adds
764 approximately eight kilobytes to the kernel image.
765
766config SCHED_SMT
767 bool "SMT (Hyperthreading) scheduler support"
b089c12b 768 depends on X86_HT
8f9ca475 769 ---help---
506f1d07
SR
770 SMT scheduler support improves the CPU scheduler's decision making
771 when dealing with Intel Pentium 4 chips with HyperThreading at a
772 cost of slightly increased overhead in some places. If unsure say
773 N here.
774
775config SCHED_MC
3c2362e6
HH
776 def_bool y
777 prompt "Multi-core scheduler support"
b089c12b 778 depends on X86_HT
8f9ca475 779 ---help---
506f1d07
SR
780 Multi-core scheduler support improves the CPU scheduler's decision
781 making when dealing with multi-core CPU chips at a cost of slightly
782 increased overhead in some places. If unsure say N here.
783
784source "kernel/Kconfig.preempt"
785
786config X86_UP_APIC
787 bool "Local APIC support on uniprocessors"
e0c7ae37 788 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 789 ---help---
506f1d07
SR
790 A local APIC (Advanced Programmable Interrupt Controller) is an
791 integrated interrupt controller in the CPU. If you have a single-CPU
792 system which has a processor with a local APIC, you can say Y here to
793 enable and use it. If you say Y here even though your machine doesn't
794 have a local APIC, then the kernel will still run with no slowdown at
795 all. The local APIC supports CPU-generated self-interrupts (timer,
796 performance counters), and the NMI watchdog which detects hard
797 lockups.
798
799config X86_UP_IOAPIC
800 bool "IO-APIC support on uniprocessors"
801 depends on X86_UP_APIC
8f9ca475 802 ---help---
506f1d07
SR
803 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
804 SMP-capable replacement for PC-style interrupt controllers. Most
805 SMP systems and many recent uniprocessor systems have one.
806
807 If you have a single-CPU system with an IO-APIC, you can say Y here
808 to use it. If you say Y here even though your machine doesn't have
809 an IO-APIC, then the kernel will still run with no slowdown at all.
810
811config X86_LOCAL_APIC
3c2362e6 812 def_bool y
e0c7ae37 813 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
506f1d07
SR
814
815config X86_IO_APIC
3c2362e6 816 def_bool y
e0c7ae37 817 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
506f1d07
SR
818
819config X86_VISWS_APIC
3c2362e6 820 def_bool y
506f1d07 821 depends on X86_32 && X86_VISWS
506f1d07 822
41b9eb26
SA
823config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
824 bool "Reroute for broken boot IRQs"
41b9eb26 825 depends on X86_IO_APIC
8f9ca475 826 ---help---
41b9eb26
SA
827 This option enables a workaround that fixes a source of
828 spurious interrupts. This is recommended when threaded
829 interrupt handling is used on systems where the generation of
830 superfluous "boot interrupts" cannot be disabled.
831
832 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
833 entry in the chipset's IO-APIC is masked (as, e.g. the RT
834 kernel does during interrupt handling). On chipsets where this
835 boot IRQ generation cannot be disabled, this workaround keeps
836 the original IRQ line masked so that only the equivalent "boot
837 IRQ" is delivered to the CPUs. The workaround also tells the
838 kernel to set up the IRQ handler on the boot IRQ line. In this
839 way only one interrupt is delivered to the kernel. Otherwise
840 the spurious second interrupt may cause the kernel to bring
841 down (vital) interrupt lines.
842
843 Only affects "broken" chipsets. Interrupt sharing may be
844 increased on these systems.
845
506f1d07 846config X86_MCE
bab9bc65 847 bool "Machine Check / overheating reporting"
506f1d07 848 ---help---
bab9bc65
AK
849 Machine Check support allows the processor to notify the
850 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 851 The action the kernel takes depends on the severity of the problem,
bab9bc65 852 ranging from warning messages to halting the machine.
4efc0670 853
506f1d07 854config X86_MCE_INTEL
3c2362e6
HH
855 def_bool y
856 prompt "Intel MCE features"
c1ebf835 857 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 858 ---help---
506f1d07
SR
859 Additional support for intel specific MCE features such as
860 the thermal monitor.
861
862config X86_MCE_AMD
3c2362e6
HH
863 def_bool y
864 prompt "AMD MCE features"
c1ebf835 865 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 866 ---help---
506f1d07
SR
867 Additional support for AMD specific MCE features such as
868 the DRAM Error Threshold.
869
4efc0670 870config X86_ANCIENT_MCE
6fc108a0 871 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 872 depends on X86_32 && X86_MCE
cd13adcc
HS
873 ---help---
874 Include support for machine check handling on old Pentium 5 or WinChip
875 systems. These typically need to be enabled explicitely on the command
876 line.
4efc0670 877
b2762686
AK
878config X86_MCE_THRESHOLD
879 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 880 def_bool y
b2762686 881
ea149b36 882config X86_MCE_INJECT
c1ebf835 883 depends on X86_MCE
ea149b36
AK
884 tristate "Machine check injector support"
885 ---help---
886 Provide support for injecting machine checks for testing purposes.
887 If you don't know what a machine check is and you don't do kernel
888 QA it is safe to say n.
889
4efc0670
AK
890config X86_THERMAL_VECTOR
891 def_bool y
5bb38adc 892 depends on X86_MCE_INTEL
4efc0670 893
506f1d07
SR
894config VM86
895 bool "Enable VM86 support" if EMBEDDED
896 default y
897 depends on X86_32
8f9ca475
IM
898 ---help---
899 This option is required by programs like DOSEMU to run 16-bit legacy
506f1d07 900 code on X86 processors. It also may be needed by software like
8f9ca475
IM
901 XFree86 to initialize some video cards via BIOS. Disabling this
902 option saves about 6k.
506f1d07
SR
903
904config TOSHIBA
905 tristate "Toshiba Laptop support"
906 depends on X86_32
907 ---help---
908 This adds a driver to safely access the System Management Mode of
909 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
910 not work on models with a Phoenix BIOS. The System Management Mode
911 is used to set the BIOS and power saving options on Toshiba portables.
912
913 For information on utilities to make use of this driver see the
914 Toshiba Linux utilities web site at:
915 <http://www.buzzard.org.uk/toshiba/>.
916
917 Say Y if you intend to run this kernel on a Toshiba portable.
918 Say N otherwise.
919
920config I8K
921 tristate "Dell laptop support"
506f1d07
SR
922 ---help---
923 This adds a driver to safely access the System Management Mode
924 of the CPU on the Dell Inspiron 8000. The System Management Mode
925 is used to read cpu temperature and cooling fan status and to
926 control the fans on the I8K portables.
927
928 This driver has been tested only on the Inspiron 8000 but it may
929 also work with other Dell laptops. You can force loading on other
930 models by passing the parameter `force=1' to the module. Use at
931 your own risk.
932
933 For information on utilities to make use of this driver see the
934 I8K Linux utilities web site at:
935 <http://people.debian.org/~dz/i8k/>
936
937 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
938 Say N otherwise.
939
940config X86_REBOOTFIXUPS
9ba16087
JB
941 bool "Enable X86 board specific fixups for reboot"
942 depends on X86_32
506f1d07
SR
943 ---help---
944 This enables chipset and/or board specific fixups to be done
945 in order to get reboot to work correctly. This is only needed on
946 some combinations of hardware and BIOS. The symptom, for which
947 this config is intended, is when reboot ends with a stalled/hung
948 system.
949
950 Currently, the only fixup is for the Geode machines using
5e3a77e9 951 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
952
953 Say Y if you want to enable the fixup. Currently, it's safe to
954 enable this option even if you don't need it.
955 Say N otherwise.
956
957config MICROCODE
8d86f390 958 tristate "/dev/cpu/microcode - microcode support"
506f1d07
SR
959 select FW_LOADER
960 ---help---
961 If you say Y here, you will be able to update the microcode on
80cc9f10
PO
962 certain Intel and AMD processors. The Intel support is for the
963 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
964 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
965 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
966 You will obviously need the actual microcode binary data itself
967 which is not shipped with the Linux kernel.
506f1d07 968
8d86f390
PO
969 This option selects the general module only, you need to select
970 at least one vendor specific module as well.
506f1d07
SR
971
972 To compile this driver as a module, choose M here: the
973 module will be called microcode.
974
8d86f390 975config MICROCODE_INTEL
8f9ca475
IM
976 bool "Intel microcode patch loading support"
977 depends on MICROCODE
978 default MICROCODE
979 select FW_LOADER
980 ---help---
981 This options enables microcode patch loading support for Intel
982 processors.
983
984 For latest news and information on obtaining all the required
985 Intel ingredients for this driver, check:
986 <http://www.urbanmyth.org/microcode/>.
8d86f390 987
80cc9f10 988config MICROCODE_AMD
8f9ca475
IM
989 bool "AMD microcode patch loading support"
990 depends on MICROCODE
991 select FW_LOADER
992 ---help---
993 If you select this option, microcode patch loading support for AMD
994 processors will be enabled.
80cc9f10 995
8f9ca475 996config MICROCODE_OLD_INTERFACE
3c2362e6 997 def_bool y
506f1d07 998 depends on MICROCODE
506f1d07
SR
999
1000config X86_MSR
1001 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1002 ---help---
506f1d07
SR
1003 This device gives privileged processes access to the x86
1004 Model-Specific Registers (MSRs). It is a character device with
1005 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1006 MSR accesses are directed to a specific CPU on multi-processor
1007 systems.
1008
1009config X86_CPUID
1010 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1011 ---help---
506f1d07
SR
1012 This device gives processes access to the x86 CPUID instruction to
1013 be executed on a specific processor. It is a character device
1014 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1015 /dev/cpu/31/cpuid.
1016
1017choice
1018 prompt "High Memory Support"
506f1d07 1019 default HIGHMEM64G if X86_NUMAQ
6fc108a0 1020 default HIGHMEM4G
506f1d07
SR
1021 depends on X86_32
1022
1023config NOHIGHMEM
1024 bool "off"
1025 depends on !X86_NUMAQ
1026 ---help---
1027 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1028 However, the address space of 32-bit x86 processors is only 4
1029 Gigabytes large. That means that, if you have a large amount of
1030 physical memory, not all of it can be "permanently mapped" by the
1031 kernel. The physical memory that's not permanently mapped is called
1032 "high memory".
1033
1034 If you are compiling a kernel which will never run on a machine with
1035 more than 1 Gigabyte total physical RAM, answer "off" here (default
1036 choice and suitable for most users). This will result in a "3GB/1GB"
1037 split: 3GB are mapped so that each process sees a 3GB virtual memory
1038 space and the remaining part of the 4GB virtual memory space is used
1039 by the kernel to permanently map as much physical memory as
1040 possible.
1041
1042 If the machine has between 1 and 4 Gigabytes physical RAM, then
1043 answer "4GB" here.
1044
1045 If more than 4 Gigabytes is used then answer "64GB" here. This
1046 selection turns Intel PAE (Physical Address Extension) mode on.
1047 PAE implements 3-level paging on IA32 processors. PAE is fully
1048 supported by Linux, PAE mode is implemented on all recent Intel
1049 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1050 then the kernel will not boot on CPUs that don't support PAE!
1051
1052 The actual amount of total physical memory will either be
1053 auto detected or can be forced by using a kernel command line option
1054 such as "mem=256M". (Try "man bootparam" or see the documentation of
1055 your boot loader (lilo or loadlin) about how to pass options to the
1056 kernel at boot time.)
1057
1058 If unsure, say "off".
1059
1060config HIGHMEM4G
1061 bool "4GB"
1062 depends on !X86_NUMAQ
8f9ca475 1063 ---help---
506f1d07
SR
1064 Select this if you have a 32-bit processor and between 1 and 4
1065 gigabytes of physical RAM.
1066
1067config HIGHMEM64G
1068 bool "64GB"
1069 depends on !M386 && !M486
1070 select X86_PAE
8f9ca475 1071 ---help---
506f1d07
SR
1072 Select this if you have a 32-bit processor and more than 4
1073 gigabytes of physical RAM.
1074
1075endchoice
1076
1077choice
1078 depends on EXPERIMENTAL
1079 prompt "Memory split" if EMBEDDED
1080 default VMSPLIT_3G
1081 depends on X86_32
8f9ca475 1082 ---help---
506f1d07
SR
1083 Select the desired split between kernel and user memory.
1084
1085 If the address range available to the kernel is less than the
1086 physical memory installed, the remaining memory will be available
1087 as "high memory". Accessing high memory is a little more costly
1088 than low memory, as it needs to be mapped into the kernel first.
1089 Note that increasing the kernel address space limits the range
1090 available to user programs, making the address space there
1091 tighter. Selecting anything other than the default 3G/1G split
1092 will also likely make your kernel incompatible with binary-only
1093 kernel modules.
1094
1095 If you are not absolutely sure what you are doing, leave this
1096 option alone!
1097
1098 config VMSPLIT_3G
1099 bool "3G/1G user/kernel split"
1100 config VMSPLIT_3G_OPT
1101 depends on !X86_PAE
1102 bool "3G/1G user/kernel split (for full 1G low memory)"
1103 config VMSPLIT_2G
1104 bool "2G/2G user/kernel split"
1105 config VMSPLIT_2G_OPT
1106 depends on !X86_PAE
1107 bool "2G/2G user/kernel split (for full 2G low memory)"
1108 config VMSPLIT_1G
1109 bool "1G/3G user/kernel split"
1110endchoice
1111
1112config PAGE_OFFSET
1113 hex
1114 default 0xB0000000 if VMSPLIT_3G_OPT
1115 default 0x80000000 if VMSPLIT_2G
1116 default 0x78000000 if VMSPLIT_2G_OPT
1117 default 0x40000000 if VMSPLIT_1G
1118 default 0xC0000000
1119 depends on X86_32
1120
1121config HIGHMEM
3c2362e6 1122 def_bool y
506f1d07 1123 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1124
1125config X86_PAE
9ba16087 1126 bool "PAE (Physical Address Extension) Support"
506f1d07 1127 depends on X86_32 && !HIGHMEM4G
8f9ca475 1128 ---help---
506f1d07
SR
1129 PAE is required for NX support, and furthermore enables
1130 larger swapspace support for non-overcommit purposes. It
1131 has the cost of more pagetable lookup overhead, and also
1132 consumes more pagetable space per process.
1133
600715dc 1134config ARCH_PHYS_ADDR_T_64BIT
8f9ca475 1135 def_bool X86_64 || X86_PAE
600715dc 1136
9e899816
NP
1137config DIRECT_GBPAGES
1138 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1139 default y
1140 depends on X86_64
8f9ca475 1141 ---help---
9e899816
NP
1142 Allow the kernel linear mapping to use 1GB pages on CPUs that
1143 support it. This can improve the kernel's performance a tiny bit by
1144 reducing TLB pressure. If in doubt, say "Y".
1145
506f1d07
SR
1146# Common NUMA Features
1147config NUMA
fd51b2d7 1148 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1149 depends on SMP
604d2055 1150 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
0699eae1 1151 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
8f9ca475 1152 ---help---
506f1d07 1153 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1154
506f1d07
SR
1155 The kernel will try to allocate memory used by a CPU on the
1156 local memory controller of the CPU and add some more
1157 NUMA awareness to the kernel.
1158
c280ea5e 1159 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1160 (or later), AMD Opteron, or EM64T NUMA.
1161
1162 For 32-bit this is only needed on (rare) 32-bit-only platforms
1163 that support NUMA topologies, such as NUMAQ / Summit, or if you
1164 boot a 32-bit kernel on a 64-bit NUMA platform.
1165
1166 Otherwise, you should say N.
506f1d07
SR
1167
1168comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1169 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1170
1171config K8_NUMA
3c2362e6
HH
1172 def_bool y
1173 prompt "Old style AMD Opteron NUMA detection"
1174 depends on X86_64 && NUMA && PCI
8f9ca475
IM
1175 ---help---
1176 Enable K8 NUMA node topology detection. You should say Y here if
1177 you have a multi processor AMD K8 system. This uses an old
1178 method to read the NUMA configuration directly from the builtin
1179 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1180 instead, which also takes priority if both are compiled in.
506f1d07
SR
1181
1182config X86_64_ACPI_NUMA
3c2362e6
HH
1183 def_bool y
1184 prompt "ACPI NUMA detection"
506f1d07
SR
1185 depends on X86_64 && NUMA && ACPI && PCI
1186 select ACPI_NUMA
8f9ca475 1187 ---help---
506f1d07
SR
1188 Enable ACPI SRAT based node topology detection.
1189
6ec6e0d9
SS
1190# Some NUMA nodes have memory ranges that span
1191# other nodes. Even though a pfn is valid and
1192# between a node's start and end pfns, it may not
1193# reside on that node. See memmap_init_zone()
1194# for details.
1195config NODES_SPAN_OTHER_NODES
1196 def_bool y
1197 depends on X86_64_ACPI_NUMA
1198
506f1d07
SR
1199config NUMA_EMU
1200 bool "NUMA emulation"
1201 depends on X86_64 && NUMA
8f9ca475 1202 ---help---
506f1d07
SR
1203 Enable NUMA emulation. A flat machine will be split
1204 into virtual nodes when booted with "numa=fake=N", where N is the
1205 number of nodes. This is only useful for debugging.
1206
1207config NODES_SHIFT
d25e26b6 1208 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1209 range 1 10
1210 default "10" if MAXSMP
506f1d07
SR
1211 default "6" if X86_64
1212 default "4" if X86_NUMAQ
1213 default "3"
1214 depends on NEED_MULTIPLE_NODES
8f9ca475 1215 ---help---
1184dc2f 1216 Specify the maximum number of NUMA Nodes available on the target
692105b8 1217 system. Increases memory reserved to accommodate various tables.
506f1d07 1218
c1329375 1219config HAVE_ARCH_BOOTMEM
3c2362e6 1220 def_bool y
506f1d07 1221 depends on X86_32 && NUMA
506f1d07
SR
1222
1223config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1224 def_bool y
506f1d07 1225 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1226
1227config NEED_NODE_MEMMAP_SIZE
3c2362e6 1228 def_bool y
506f1d07 1229 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07
SR
1230
1231config HAVE_ARCH_ALLOC_REMAP
3c2362e6 1232 def_bool y
506f1d07 1233 depends on X86_32 && NUMA
506f1d07
SR
1234
1235config ARCH_FLATMEM_ENABLE
1236 def_bool y
99809963 1237 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
506f1d07
SR
1238
1239config ARCH_DISCONTIGMEM_ENABLE
1240 def_bool y
b263295d 1241 depends on NUMA && X86_32
506f1d07
SR
1242
1243config ARCH_DISCONTIGMEM_DEFAULT
1244 def_bool y
b263295d
CL
1245 depends on NUMA && X86_32
1246
9492587c
KH
1247config ARCH_PROC_KCORE_TEXT
1248 def_bool y
1249 depends on X86_64 && PROC_KCORE
1250
b263295d
CL
1251config ARCH_SPARSEMEM_DEFAULT
1252 def_bool y
1253 depends on X86_64
506f1d07
SR
1254
1255config ARCH_SPARSEMEM_ENABLE
1256 def_bool y
4272ebfb 1257 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
506f1d07
SR
1258 select SPARSEMEM_STATIC if X86_32
1259 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1260
1261config ARCH_SELECT_MEMORY_MODEL
1262 def_bool y
b263295d 1263 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1264
1265config ARCH_MEMORY_PROBE
1266 def_bool X86_64
1267 depends on MEMORY_HOTPLUG
1268
a29815a3
AK
1269config ILLEGAL_POINTER_VALUE
1270 hex
1271 default 0 if X86_32
1272 default 0xdead000000000000 if X86_64
1273
506f1d07
SR
1274source "mm/Kconfig"
1275
1276config HIGHPTE
1277 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1278 depends on HIGHMEM
8f9ca475 1279 ---help---
506f1d07
SR
1280 The VM uses one page table entry for each page of physical memory.
1281 For systems with a lot of RAM, this can be wasteful of precious
1282 low memory. Setting this option will put user-space page table
1283 entries in high memory.
1284
9f077871 1285config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1286 bool "Check for low memory corruption"
1287 ---help---
1288 Periodically check for memory corruption in low memory, which
1289 is suspected to be caused by BIOS. Even when enabled in the
1290 configuration, it is disabled at runtime. Enable it by
1291 setting "memory_corruption_check=1" on the kernel command
1292 line. By default it scans the low 64k of memory every 60
1293 seconds; see the memory_corruption_check_size and
1294 memory_corruption_check_period parameters in
1295 Documentation/kernel-parameters.txt to adjust this.
1296
1297 When enabled with the default parameters, this option has
1298 almost no overhead, as it reserves a relatively small amount
1299 of memory and scans it infrequently. It both detects corruption
1300 and prevents it from affecting the running system.
1301
1302 It is, however, intended as a diagnostic tool; if repeatable
1303 BIOS-originated corruption always affects the same memory,
1304 you can use memmap= to prevent the kernel from using that
1305 memory.
9f077871 1306
c885df50 1307config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1308 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1309 depends on X86_CHECK_BIOS_CORRUPTION
1310 default y
8f9ca475
IM
1311 ---help---
1312 Set whether the default state of memory_corruption_check is
1313 on or off.
c885df50 1314
fc381519 1315config X86_RESERVE_LOW_64K
8f9ca475 1316 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
fc381519 1317 default y
8f9ca475
IM
1318 ---help---
1319 Reserve the first 64K of physical RAM on BIOSes that are known
1320 to potentially corrupt that memory range. A numbers of BIOSes are
1321 known to utilize this area during suspend/resume, so it must not
1322 be used by the kernel.
fc381519 1323
8f9ca475
IM
1324 Set this to N if you are absolutely sure that you trust the BIOS
1325 to get all its memory reservations and usages right.
fc381519 1326
8f9ca475
IM
1327 If you have doubts about the BIOS (e.g. suspend/resume does not
1328 work or there's kernel crashes after certain hardware hotplug
1329 events) and it's not AMI or Phoenix, then you might want to enable
1330 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1331 corruption patterns.
fc381519 1332
8f9ca475 1333 Say Y if unsure.
fc381519 1334
506f1d07
SR
1335config MATH_EMULATION
1336 bool
1337 prompt "Math emulation" if X86_32
1338 ---help---
1339 Linux can emulate a math coprocessor (used for floating point
1340 operations) if you don't have one. 486DX and Pentium processors have
1341 a math coprocessor built in, 486SX and 386 do not, unless you added
1342 a 487DX or 387, respectively. (The messages during boot time can
1343 give you some hints here ["man dmesg"].) Everyone needs either a
1344 coprocessor or this emulation.
1345
1346 If you don't have a math coprocessor, you need to say Y here; if you
1347 say Y here even though you have a coprocessor, the coprocessor will
1348 be used nevertheless. (This behavior can be changed with the kernel
1349 command line option "no387", which comes handy if your coprocessor
1350 is broken. Try "man bootparam" or see the documentation of your boot
1351 loader (lilo or loadlin) about how to pass options to the kernel at
1352 boot time.) This means that it is a good idea to say Y here if you
1353 intend to use this kernel on different machines.
1354
1355 More information about the internals of the Linux math coprocessor
1356 emulation can be found in <file:arch/x86/math-emu/README>.
1357
1358 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1359 kernel, it won't hurt.
1360
1361config MTRR
6fc108a0 1362 def_bool y
c03cb314 1363 prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
506f1d07
SR
1364 ---help---
1365 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1366 the Memory Type Range Registers (MTRRs) may be used to control
1367 processor access to memory ranges. This is most useful if you have
1368 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1369 allows bus write transfers to be combined into a larger transfer
1370 before bursting over the PCI/AGP bus. This can increase performance
1371 of image write operations 2.5 times or more. Saying Y here creates a
1372 /proc/mtrr file which may be used to manipulate your processor's
1373 MTRRs. Typically the X server should use this.
1374
1375 This code has a reasonably generic interface so that similar
1376 control registers on other processors can be easily supported
1377 as well:
1378
1379 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1380 Registers (ARRs) which provide a similar functionality to MTRRs. For
1381 these, the ARRs are used to emulate the MTRRs.
1382 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1383 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1384 write-combining. All of these processors are supported by this code
1385 and it makes sense to say Y here if you have one of them.
1386
1387 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1388 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1389 can lead to all sorts of problems, so it's good to say Y here.
1390
1391 You can safely say Y even if your machine doesn't have MTRRs, you'll
1392 just add about 9 KB to your kernel.
1393
7225e751 1394 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1395
95ffa243 1396config MTRR_SANITIZER
2ffb3501 1397 def_bool y
95ffa243
YL
1398 prompt "MTRR cleanup support"
1399 depends on MTRR
8f9ca475 1400 ---help---
aba3728c
TG
1401 Convert MTRR layout from continuous to discrete, so X drivers can
1402 add writeback entries.
95ffa243 1403
aba3728c 1404 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1405 The largest mtrr entry size for a continuous block can be set with
aba3728c 1406 mtrr_chunk_size.
95ffa243 1407
2ffb3501 1408 If unsure, say Y.
95ffa243
YL
1409
1410config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1411 int "MTRR cleanup enable value (0-1)"
1412 range 0 1
1413 default "0"
95ffa243 1414 depends on MTRR_SANITIZER
8f9ca475 1415 ---help---
f5098d62 1416 Enable mtrr cleanup default value
95ffa243 1417
12031a62
YL
1418config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1419 int "MTRR cleanup spare reg num (0-7)"
1420 range 0 7
1421 default "1"
1422 depends on MTRR_SANITIZER
8f9ca475 1423 ---help---
12031a62 1424 mtrr cleanup spare entries default, it can be changed via
aba3728c 1425 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1426
2e5d9c85 1427config X86_PAT
6fc108a0 1428 def_bool y
c03cb314 1429 prompt "x86 PAT support" if EMBEDDED
2a8a2719 1430 depends on MTRR
8f9ca475 1431 ---help---
2e5d9c85 1432 Use PAT attributes to setup page level cache control.
042b78e4 1433
2e5d9c85 1434 PATs are the modern equivalents of MTRRs and are much more
1435 flexible than MTRRs.
1436
1437 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1438 spontaneous reboots) or a non-working video driver.
2e5d9c85 1439
1440 If unsure, say Y.
1441
46cf98cd
VP
1442config ARCH_USES_PG_UNCACHED
1443 def_bool y
1444 depends on X86_PAT
1445
506f1d07 1446config EFI
9ba16087 1447 bool "EFI runtime service support"
5b83683f 1448 depends on ACPI
506f1d07 1449 ---help---
8f9ca475
IM
1450 This enables the kernel to use EFI runtime services that are
1451 available (such as the EFI variable services).
506f1d07 1452
8f9ca475
IM
1453 This option is only useful on systems that have EFI firmware.
1454 In addition, you should use the latest ELILO loader available
1455 at <http://elilo.sourceforge.net> in order to take advantage
1456 of EFI runtime services. However, even with this option, the
1457 resultant kernel should continue to boot on existing non-EFI
1458 platforms.
506f1d07 1459
506f1d07 1460config SECCOMP
3c2362e6
HH
1461 def_bool y
1462 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1463 ---help---
506f1d07
SR
1464 This kernel feature is useful for number crunching applications
1465 that may need to compute untrusted bytecode during their
1466 execution. By using pipes or other transports made available to
1467 the process as file descriptors supporting the read/write
1468 syscalls, it's possible to isolate those applications in
1469 their own address space using seccomp. Once seccomp is
9c0bbee8 1470 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1471 and the task is only allowed to execute a few safe syscalls
1472 defined by each seccomp mode.
1473
1474 If unsure, say Y. Only embedded should say N here.
1475
1476config CC_STACKPROTECTOR
1477 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
8f9ca475
IM
1478 ---help---
1479 This option turns on the -fstack-protector GCC feature. This
113c5413
IM
1480 feature puts, at the beginning of functions, a canary value on
1481 the stack just before the return address, and validates
506f1d07
SR
1482 the value just before actually returning. Stack based buffer
1483 overflows (that need to overwrite this return address) now also
1484 overwrite the canary, which gets detected and the attack is then
1485 neutralized via a kernel panic.
1486
1487 This feature requires gcc version 4.2 or above, or a distribution
1488 gcc with the feature backported. Older versions are automatically
113c5413
IM
1489 detected and for those versions, this configuration option is
1490 ignored. (and a warning is printed during bootup)
506f1d07
SR
1491
1492source kernel/Kconfig.hz
1493
1494config KEXEC
1495 bool "kexec system call"
8f9ca475 1496 ---help---
506f1d07
SR
1497 kexec is a system call that implements the ability to shutdown your
1498 current kernel, and to start another kernel. It is like a reboot
1499 but it is independent of the system firmware. And like a reboot
1500 you can start any kernel with it, not just Linux.
1501
1502 The name comes from the similarity to the exec system call.
1503
1504 It is an ongoing process to be certain the hardware in a machine
1505 is properly shutdown, so do not be surprised if this code does not
1506 initially work for you. It may help to enable device hotplugging
1507 support. As of this writing the exact hardware interface is
1508 strongly in flux, so no good recommendation can be made.
1509
1510config CRASH_DUMP
04b69447 1511 bool "kernel crash dumps"
506f1d07 1512 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1513 ---help---
506f1d07
SR
1514 Generate crash dump after being started by kexec.
1515 This should be normally only set in special crash dump kernels
1516 which are loaded in the main kernel with kexec-tools into
1517 a specially reserved region and then later executed after
1518 a crash by kdump/kexec. The crash dump kernel must be compiled
1519 to a memory address not used by the main kernel or BIOS using
1520 PHYSICAL_START, or it must be built as a relocatable image
1521 (CONFIG_RELOCATABLE=y).
1522 For more details see Documentation/kdump/kdump.txt
1523
3ab83521
HY
1524config KEXEC_JUMP
1525 bool "kexec jump (EXPERIMENTAL)"
1526 depends on EXPERIMENTAL
fee7b0d8 1527 depends on KEXEC && HIBERNATION
8f9ca475 1528 ---help---
89081d17
HY
1529 Jump between original kernel and kexeced kernel and invoke
1530 code in physical address mode via KEXEC
3ab83521 1531
506f1d07
SR
1532config PHYSICAL_START
1533 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
ceefccc9 1534 default "0x1000000"
8f9ca475 1535 ---help---
506f1d07
SR
1536 This gives the physical address where the kernel is loaded.
1537
1538 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1539 bzImage will decompress itself to above physical address and
1540 run from there. Otherwise, bzImage will run from the address where
1541 it has been loaded by the boot loader and will ignore above physical
1542 address.
1543
1544 In normal kdump cases one does not have to set/change this option
1545 as now bzImage can be compiled as a completely relocatable image
1546 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1547 address. This option is mainly useful for the folks who don't want
1548 to use a bzImage for capturing the crash dump and want to use a
1549 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1550 to be specifically compiled to run from a specific memory area
1551 (normally a reserved region) and this option comes handy.
1552
ceefccc9
PA
1553 So if you are using bzImage for capturing the crash dump,
1554 leave the value here unchanged to 0x1000000 and set
1555 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1556 for capturing the crash dump change this value to start of
1557 the reserved region. In other words, it can be set based on
1558 the "X" value as specified in the "crashkernel=YM@XM"
1559 command line boot parameter passed to the panic-ed
1560 kernel. Please take a look at Documentation/kdump/kdump.txt
1561 for more details about crash dumps.
506f1d07
SR
1562
1563 Usage of bzImage for capturing the crash dump is recommended as
1564 one does not have to build two kernels. Same kernel can be used
1565 as production kernel and capture kernel. Above option should have
1566 gone away after relocatable bzImage support is introduced. But it
1567 is present because there are users out there who continue to use
1568 vmlinux for dump capture. This option should go away down the
1569 line.
1570
1571 Don't change this unless you know what you are doing.
1572
1573config RELOCATABLE
26717808
PA
1574 bool "Build a relocatable kernel"
1575 default y
8f9ca475 1576 ---help---
506f1d07
SR
1577 This builds a kernel image that retains relocation information
1578 so it can be loaded someplace besides the default 1MB.
1579 The relocations tend to make the kernel binary about 10% larger,
1580 but are discarded at runtime.
1581
1582 One use is for the kexec on panic case where the recovery kernel
1583 must live at a different physical address than the primary
1584 kernel.
1585
1586 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1587 it has been loaded at and the compile time physical address
1588 (CONFIG_PHYSICAL_START) is ignored.
1589
845adf72
PA
1590# Relocation on x86-32 needs some additional build support
1591config X86_NEED_RELOCS
1592 def_bool y
1593 depends on X86_32 && RELOCATABLE
1594
506f1d07 1595config PHYSICAL_ALIGN
6fc108a0 1596 hex "Alignment value to which kernel should be aligned" if X86_32
ceefccc9
PA
1597 default "0x1000000"
1598 range 0x2000 0x1000000
8f9ca475 1599 ---help---
506f1d07
SR
1600 This value puts the alignment restrictions on physical address
1601 where kernel is loaded and run from. Kernel is compiled for an
1602 address which meets above alignment restriction.
1603
1604 If bootloader loads the kernel at a non-aligned address and
1605 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1606 address aligned to above value and run from there.
1607
1608 If bootloader loads the kernel at a non-aligned address and
1609 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1610 load address and decompress itself to the address it has been
1611 compiled for and run from there. The address for which kernel is
1612 compiled already meets above alignment restrictions. Hence the
1613 end result is that kernel runs from a physical address meeting
1614 above alignment restrictions.
1615
1616 Don't change this unless you know what you are doing.
1617
1618config HOTPLUG_CPU
7c13e6a3 1619 bool "Support for hot-pluggable CPUs"
4b19ed91 1620 depends on SMP && HOTPLUG
506f1d07 1621 ---help---
7c13e6a3
DS
1622 Say Y here to allow turning CPUs off and on. CPUs can be
1623 controlled through /sys/devices/system/cpu.
1624 ( Note: power management support will enable this option
1625 automatically on SMP systems. )
1626 Say N if you want to disable CPU hotplug.
506f1d07
SR
1627
1628config COMPAT_VDSO
3c2362e6
HH
1629 def_bool y
1630 prompt "Compat VDSO support"
af65d648 1631 depends on X86_32 || IA32_EMULATION
8f9ca475 1632 ---help---
af65d648 1633 Map the 32-bit VDSO to the predictable old-style address too.
e84446de 1634
506f1d07
SR
1635 Say N here if you are running a sufficiently recent glibc
1636 version (2.3.3 or later), to remove the high-mapped
1637 VDSO mapping and to exclusively use the randomized VDSO.
1638
1639 If unsure, say Y.
1640
516cbf37
TB
1641config CMDLINE_BOOL
1642 bool "Built-in kernel command line"
8f9ca475 1643 ---help---
516cbf37
TB
1644 Allow for specifying boot arguments to the kernel at
1645 build time. On some systems (e.g. embedded ones), it is
1646 necessary or convenient to provide some or all of the
1647 kernel boot arguments with the kernel itself (that is,
1648 to not rely on the boot loader to provide them.)
1649
1650 To compile command line arguments into the kernel,
1651 set this option to 'Y', then fill in the
1652 the boot arguments in CONFIG_CMDLINE.
1653
1654 Systems with fully functional boot loaders (i.e. non-embedded)
1655 should leave this option set to 'N'.
1656
1657config CMDLINE
1658 string "Built-in kernel command string"
1659 depends on CMDLINE_BOOL
1660 default ""
8f9ca475 1661 ---help---
516cbf37
TB
1662 Enter arguments here that should be compiled into the kernel
1663 image and used at boot time. If the boot loader provides a
1664 command line at boot time, it is appended to this string to
1665 form the full kernel command line, when the system boots.
1666
1667 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1668 change this behavior.
1669
1670 In most cases, the command line (whether built-in or provided
1671 by the boot loader) should specify the device for the root
1672 file system.
1673
1674config CMDLINE_OVERRIDE
1675 bool "Built-in command line overrides boot loader arguments"
516cbf37 1676 depends on CMDLINE_BOOL
8f9ca475 1677 ---help---
516cbf37
TB
1678 Set this option to 'Y' to have the kernel ignore the boot loader
1679 command line, and use ONLY the built-in command line.
1680
1681 This is used to work around broken boot loaders. This should
1682 be set to 'N' under normal conditions.
1683
506f1d07
SR
1684endmenu
1685
1686config ARCH_ENABLE_MEMORY_HOTPLUG
1687 def_bool y
1688 depends on X86_64 || (X86_32 && HIGHMEM)
1689
35551053
GH
1690config ARCH_ENABLE_MEMORY_HOTREMOVE
1691 def_bool y
1692 depends on MEMORY_HOTPLUG
1693
506f1d07
SR
1694config HAVE_ARCH_EARLY_PFN_TO_NID
1695 def_bool X86_64
1696 depends on NUMA
1697
e534c7c5
LS
1698config USE_PERCPU_NUMA_NODE_ID
1699 def_bool X86_64
1700 depends on NUMA
1701
da85f865 1702menu "Power management and ACPI options"
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SR
1703
1704config ARCH_HIBERNATION_HEADER
3c2362e6 1705 def_bool y
e279b6c1 1706 depends on X86_64 && HIBERNATION
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SR
1707
1708source "kernel/power/Kconfig"
1709
1710source "drivers/acpi/Kconfig"
1711
efafc8b2
FT
1712source "drivers/sfi/Kconfig"
1713
a6b68076 1714config X86_APM_BOOT
6fc108a0 1715 def_bool y
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1716 depends on APM || APM_MODULE
1717
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SR
1718menuconfig APM
1719 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 1720 depends on X86_32 && PM_SLEEP
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SR
1721 ---help---
1722 APM is a BIOS specification for saving power using several different
1723 techniques. This is mostly useful for battery powered laptops with
1724 APM compliant BIOSes. If you say Y here, the system time will be
1725 reset after a RESUME operation, the /proc/apm device will provide
1726 battery status information, and user-space programs will receive
1727 notification of APM "events" (e.g. battery status change).
1728
1729 If you select "Y" here, you can disable actual use of the APM
1730 BIOS by passing the "apm=off" option to the kernel at boot time.
1731
1732 Note that the APM support is almost completely disabled for
1733 machines with more than one CPU.
1734
1735 In order to use APM, you will need supporting software. For location
53471121 1736 and more information, read <file:Documentation/power/pm.txt> and the
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SR
1737 Battery Powered Linux mini-HOWTO, available from
1738 <http://www.tldp.org/docs.html#howto>.
1739
1740 This driver does not spin down disk drives (see the hdparm(8)
1741 manpage ("man 8 hdparm") for that), and it doesn't turn off
1742 VESA-compliant "green" monitors.
1743
1744 This driver does not support the TI 4000M TravelMate and the ACER
1745 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1746 desktop machines also don't have compliant BIOSes, and this driver
1747 may cause those machines to panic during the boot phase.
1748
1749 Generally, if you don't have a battery in your machine, there isn't
1750 much point in using this driver and you should say N. If you get
1751 random kernel OOPSes or reboots that don't seem to be related to
1752 anything, try disabling/enabling this option (or disabling/enabling
1753 APM in your BIOS).
1754
1755 Some other things you should try when experiencing seemingly random,
1756 "weird" problems:
1757
1758 1) make sure that you have enough swap space and that it is
1759 enabled.
1760 2) pass the "no-hlt" option to the kernel
1761 3) switch on floating point emulation in the kernel and pass
1762 the "no387" option to the kernel
1763 4) pass the "floppy=nodma" option to the kernel
1764 5) pass the "mem=4M" option to the kernel (thereby disabling
1765 all but the first 4 MB of RAM)
1766 6) make sure that the CPU is not over clocked.
1767 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1768 8) disable the cache from your BIOS settings
1769 9) install a fan for the video card or exchange video RAM
1770 10) install a better fan for the CPU
1771 11) exchange RAM chips
1772 12) exchange the motherboard.
1773
1774 To compile this driver as a module, choose M here: the
1775 module will be called apm.
1776
1777if APM
1778
1779config APM_IGNORE_USER_SUSPEND
1780 bool "Ignore USER SUSPEND"
8f9ca475 1781 ---help---
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SR
1782 This option will ignore USER SUSPEND requests. On machines with a
1783 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1784 series notebooks, it is necessary to say Y because of a BIOS bug.
1785
1786config APM_DO_ENABLE
1787 bool "Enable PM at boot time"
1788 ---help---
1789 Enable APM features at boot time. From page 36 of the APM BIOS
1790 specification: "When disabled, the APM BIOS does not automatically
1791 power manage devices, enter the Standby State, enter the Suspend
1792 State, or take power saving steps in response to CPU Idle calls."
1793 This driver will make CPU Idle calls when Linux is idle (unless this
1794 feature is turned off -- see "Do CPU IDLE calls", below). This
1795 should always save battery power, but more complicated APM features
1796 will be dependent on your BIOS implementation. You may need to turn
1797 this option off if your computer hangs at boot time when using APM
1798 support, or if it beeps continuously instead of suspending. Turn
1799 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1800 T400CDT. This is off by default since most machines do fine without
1801 this feature.
1802
1803config APM_CPU_IDLE
1804 bool "Make CPU Idle calls when idle"
8f9ca475 1805 ---help---
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SR
1806 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1807 On some machines, this can activate improved power savings, such as
1808 a slowed CPU clock rate, when the machine is idle. These idle calls
1809 are made after the idle loop has run for some length of time (e.g.,
1810 333 mS). On some machines, this will cause a hang at boot time or
1811 whenever the CPU becomes idle. (On machines with more than one CPU,
1812 this option does nothing.)
1813
1814config APM_DISPLAY_BLANK
1815 bool "Enable console blanking using APM"
8f9ca475 1816 ---help---
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SR
1817 Enable console blanking using the APM. Some laptops can use this to
1818 turn off the LCD backlight when the screen blanker of the Linux
1819 virtual console blanks the screen. Note that this is only used by
1820 the virtual console screen blanker, and won't turn off the backlight
1821 when using the X Window system. This also doesn't have anything to
1822 do with your VESA-compliant power-saving monitor. Further, this
1823 option doesn't work for all laptops -- it might not turn off your
1824 backlight at all, or it might print a lot of errors to the console,
1825 especially if you are using gpm.
1826
1827config APM_ALLOW_INTS
1828 bool "Allow interrupts during APM BIOS calls"
8f9ca475 1829 ---help---
e279b6c1
SR
1830 Normally we disable external interrupts while we are making calls to
1831 the APM BIOS as a measure to lessen the effects of a badly behaving
1832 BIOS implementation. The BIOS should reenable interrupts if it
1833 needs to. Unfortunately, some BIOSes do not -- especially those in
1834 many of the newer IBM Thinkpads. If you experience hangs when you
1835 suspend, try setting this to Y. Otherwise, say N.
1836
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SR
1837endif # APM
1838
1839source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1840
1841source "drivers/cpuidle/Kconfig"
1842
27471fdb
AH
1843source "drivers/idle/Kconfig"
1844
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SR
1845endmenu
1846
1847
1848menu "Bus options (PCI etc.)"
1849
1850config PCI
1ac97018 1851 bool "PCI support"
1c858087 1852 default y
e279b6c1 1853 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
8f9ca475 1854 ---help---
e279b6c1
SR
1855 Find out whether you have a PCI motherboard. PCI is the name of a
1856 bus system, i.e. the way the CPU talks to the other stuff inside
1857 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1858 VESA. If you have PCI, say Y, otherwise N.
1859
e279b6c1
SR
1860choice
1861 prompt "PCI access mode"
efefa6f6 1862 depends on X86_32 && PCI
e279b6c1
SR
1863 default PCI_GOANY
1864 ---help---
1865 On PCI systems, the BIOS can be used to detect the PCI devices and
1866 determine their configuration. However, some old PCI motherboards
1867 have BIOS bugs and may crash if this is done. Also, some embedded
1868 PCI-based systems don't have any BIOS at all. Linux can also try to
1869 detect the PCI hardware directly without using the BIOS.
1870
1871 With this option, you can specify how Linux should detect the
1872 PCI devices. If you choose "BIOS", the BIOS will be used,
1873 if you choose "Direct", the BIOS won't be used, and if you
1874 choose "MMConfig", then PCI Express MMCONFIG will be used.
1875 If you choose "Any", the kernel will try MMCONFIG, then the
1876 direct access method and falls back to the BIOS if that doesn't
1877 work. If unsure, go with the default, which is "Any".
1878
1879config PCI_GOBIOS
1880 bool "BIOS"
1881
1882config PCI_GOMMCONFIG
1883 bool "MMConfig"
1884
1885config PCI_GODIRECT
1886 bool "Direct"
1887
3ef0e1f8
AS
1888config PCI_GOOLPC
1889 bool "OLPC"
1890 depends on OLPC
1891
2bdd1b03
AS
1892config PCI_GOANY
1893 bool "Any"
1894
e279b6c1
SR
1895endchoice
1896
1897config PCI_BIOS
3c2362e6 1898 def_bool y
efefa6f6 1899 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
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SR
1900
1901# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1902config PCI_DIRECT
3c2362e6 1903 def_bool y
efefa6f6 1904 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
e279b6c1
SR
1905
1906config PCI_MMCONFIG
3c2362e6 1907 def_bool y
5f0db7a2 1908 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 1909
3ef0e1f8 1910config PCI_OLPC
2bdd1b03
AS
1911 def_bool y
1912 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 1913
e279b6c1 1914config PCI_DOMAINS
3c2362e6 1915 def_bool y
e279b6c1 1916 depends on PCI
e279b6c1
SR
1917
1918config PCI_MMCONFIG
1919 bool "Support mmconfig PCI config space access"
1920 depends on X86_64 && PCI && ACPI
1921
3f6ea84a
IS
1922config PCI_CNB20LE_QUIRK
1923 bool "Read CNB20LE Host Bridge Windows"
1924 depends on PCI
1925 help
1926 Read the PCI windows out of the CNB20LE host bridge. This allows
1927 PCI hotplug to work on systems with the CNB20LE chipset which do
1928 not have ACPI.
1929
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SR
1930config DMAR
1931 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
4cf2e75d 1932 depends on PCI_MSI && ACPI && EXPERIMENTAL
e279b6c1
SR
1933 help
1934 DMA remapping (DMAR) devices support enables independent address
1935 translations for Direct Memory Access (DMA) from devices.
1936 These DMA remapping devices are reported via ACPI tables
1937 and include PCI device scope covered by these DMA
1938 remapping devices.
1939
0cd5c3c8 1940config DMAR_DEFAULT_ON
f6be37fd 1941 def_bool y
0cd5c3c8
KM
1942 prompt "Enable DMA Remapping Devices by default"
1943 depends on DMAR
1944 help
1945 Selecting this option will enable a DMAR device at boot time if
1946 one is found. If this option is not selected, DMAR support can
1947 be enabled by passing intel_iommu=on to the kernel. It is
1948 recommended you say N here while the DMAR code remains
1949 experimental.
1950
62edf5dc 1951config DMAR_BROKEN_GFX_WA
6fc108a0 1952 bool "Workaround broken graphics drivers (going away soon)"
0c02a20f 1953 depends on DMAR && BROKEN
62edf5dc
DW
1954 ---help---
1955 Current Graphics drivers tend to use physical address
1956 for DMA and avoid using DMA APIs. Setting this config
1957 option permits the IOMMU driver to set a unity map for
1958 all the OS-visible memory. Hence the driver can continue
1959 to use physical addresses for DMA, at least until this
1960 option is removed in the 2.6.32 kernel.
1961
e279b6c1 1962config DMAR_FLOPPY_WA
3c2362e6 1963 def_bool y
e279b6c1 1964 depends on DMAR
8f9ca475 1965 ---help---
c7ab48d2 1966 Floppy disk drivers are known to bypass DMA API calls
8f9ca475
IM
1967 thereby failing to work when IOMMU is enabled. This
1968 workaround will setup a 1:1 mapping for the first
c7ab48d2 1969 16MiB to make floppy (an ISA device) work.
e279b6c1 1970
9fa8c481
SS
1971config INTR_REMAP
1972 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1973 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
8f9ca475
IM
1974 ---help---
1975 Supports Interrupt remapping for IO-APIC and MSI devices.
1976 To use x2apic mode in the CPU's which support x2APIC enhancements or
1977 to support platforms with CPU's having > 8 bit APIC ID, say Y.
9fa8c481 1978
e279b6c1
SR
1979source "drivers/pci/pcie/Kconfig"
1980
1981source "drivers/pci/Kconfig"
1982
1983# x86_64 have no ISA slots, but do have ISA-style DMA.
1984config ISA_DMA_API
3c2362e6 1985 def_bool y
e279b6c1
SR
1986
1987if X86_32
1988
1989config ISA
1990 bool "ISA support"
8f9ca475 1991 ---help---
e279b6c1
SR
1992 Find out whether you have ISA slots on your motherboard. ISA is the
1993 name of a bus system, i.e. the way the CPU talks to the other stuff
1994 inside your box. Other bus systems are PCI, EISA, MicroChannel
1995 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1996 newer boards don't support it. If you have ISA, say Y, otherwise N.
1997
1998config EISA
1999 bool "EISA support"
2000 depends on ISA
2001 ---help---
2002 The Extended Industry Standard Architecture (EISA) bus was
2003 developed as an open alternative to the IBM MicroChannel bus.
2004
2005 The EISA bus provided some of the features of the IBM MicroChannel
2006 bus while maintaining backward compatibility with cards made for
2007 the older ISA bus. The EISA bus saw limited use between 1988 and
2008 1995 when it was made obsolete by the PCI bus.
2009
2010 Say Y here if you are building a kernel for an EISA-based machine.
2011
2012 Otherwise, say N.
2013
2014source "drivers/eisa/Kconfig"
2015
2016config MCA
72ee6ebb 2017 bool "MCA support"
8f9ca475 2018 ---help---
e279b6c1
SR
2019 MicroChannel Architecture is found in some IBM PS/2 machines and
2020 laptops. It is a bus system similar to PCI or ISA. See
2021 <file:Documentation/mca.txt> (and especially the web page given
2022 there) before attempting to build an MCA bus kernel.
2023
2024source "drivers/mca/Kconfig"
2025
2026config SCx200
2027 tristate "NatSemi SCx200 support"
8f9ca475 2028 ---help---
e279b6c1
SR
2029 This provides basic support for National Semiconductor's
2030 (now AMD's) Geode processors. The driver probes for the
2031 PCI-IDs of several on-chip devices, so its a good dependency
2032 for other scx200_* drivers.
2033
2034 If compiled as a module, the driver is named scx200.
2035
2036config SCx200HR_TIMER
2037 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2038 depends on SCx200 && GENERIC_TIME
2039 default y
8f9ca475 2040 ---help---
e279b6c1
SR
2041 This driver provides a clocksource built upon the on-chip
2042 27MHz high-resolution timer. Its also a workaround for
2043 NSC Geode SC-1100's buggy TSC, which loses time when the
2044 processor goes idle (as is done by the scheduler). The
2045 other workaround is idle=poll boot option.
2046
3ef0e1f8
AS
2047config OLPC
2048 bool "One Laptop Per Child support"
3c554946 2049 select GPIOLIB
8f9ca475 2050 ---help---
3ef0e1f8
AS
2051 Add support for detecting the unique features of the OLPC
2052 XO hardware.
2053
bc0120fd
SR
2054endif # X86_32
2055
e279b6c1
SR
2056config K8_NB
2057 def_bool y
0e152cd7 2058 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2059
2060source "drivers/pcmcia/Kconfig"
2061
2062source "drivers/pci/hotplug/Kconfig"
2063
2064endmenu
2065
2066
2067menu "Executable file formats / Emulations"
2068
2069source "fs/Kconfig.binfmt"
2070
2071config IA32_EMULATION
2072 bool "IA32 Emulation"
2073 depends on X86_64
a97f52e6 2074 select COMPAT_BINFMT_ELF
8f9ca475 2075 ---help---
e279b6c1
SR
2076 Include code to run 32-bit programs under a 64-bit kernel. You should
2077 likely turn this on, unless you're 100% sure that you don't have any
2078 32-bit programs left.
2079
2080config IA32_AOUT
8f9ca475
IM
2081 tristate "IA32 a.out support"
2082 depends on IA32_EMULATION
2083 ---help---
2084 Support old a.out binaries in the 32bit emulation.
e279b6c1
SR
2085
2086config COMPAT
3c2362e6 2087 def_bool y
e279b6c1 2088 depends on IA32_EMULATION
e279b6c1
SR
2089
2090config COMPAT_FOR_U64_ALIGNMENT
2091 def_bool COMPAT
2092 depends on X86_64
2093
2094config SYSVIPC_COMPAT
3c2362e6 2095 def_bool y
b8992195 2096 depends on COMPAT && SYSVIPC
e279b6c1
SR
2097
2098endmenu
2099
2100
e5beae16
KP
2101config HAVE_ATOMIC_IOMAP
2102 def_bool y
2103 depends on X86_32
2104
e279b6c1
SR
2105source "net/Kconfig"
2106
2107source "drivers/Kconfig"
2108
2109source "drivers/firmware/Kconfig"
2110
2111source "fs/Kconfig"
2112
e279b6c1
SR
2113source "arch/x86/Kconfig.debug"
2114
2115source "security/Kconfig"
2116
2117source "crypto/Kconfig"
2118
edf88417
AK
2119source "arch/x86/kvm/Kconfig"
2120
e279b6c1 2121source "lib/Kconfig"
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