Merge tag 'please-pull-misc-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / arch / x86 / Kconfig
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH != "i386"
5 ---help---
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9 config X86_32
10 def_bool y
11 depends on !64BIT
12 select CLKSRC_I8253
13 select HAVE_UID16
14
15 config X86_64
16 def_bool y
17 depends on 64BIT
18 select X86_DEV_DMA_OPS
19
20 ### Arch settings
21 config X86
22 def_bool y
23 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
24 select HAVE_AOUT if X86_32
25 select HAVE_UNSTABLE_SCHED_CLOCK
26 select ARCH_SUPPORTS_NUMA_BALANCING
27 select ARCH_WANTS_PROT_NUMA_PROT_NONE
28 select HAVE_IDE
29 select HAVE_OPROFILE
30 select HAVE_PCSPKR_PLATFORM
31 select HAVE_PERF_EVENTS
32 select HAVE_IOREMAP_PROT
33 select HAVE_KPROBES
34 select HAVE_MEMBLOCK
35 select HAVE_MEMBLOCK_NODE_MAP
36 select ARCH_DISCARD_MEMBLOCK
37 select ARCH_WANT_OPTIONAL_GPIOLIB
38 select ARCH_WANT_FRAME_POINTERS
39 select HAVE_DMA_ATTRS
40 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
41 select HAVE_KRETPROBES
42 select HAVE_OPTPROBES
43 select HAVE_KPROBES_ON_FTRACE
44 select HAVE_FTRACE_MCOUNT_RECORD
45 select HAVE_FENTRY if X86_64
46 select HAVE_C_RECORDMCOUNT
47 select HAVE_DYNAMIC_FTRACE
48 select HAVE_DYNAMIC_FTRACE_WITH_REGS
49 select HAVE_FUNCTION_TRACER
50 select HAVE_FUNCTION_GRAPH_TRACER
51 select HAVE_FUNCTION_GRAPH_FP_TEST
52 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
53 select HAVE_SYSCALL_TRACEPOINTS
54 select SYSCTL_EXCEPTION_TRACE
55 select HAVE_KVM
56 select HAVE_ARCH_KGDB
57 select HAVE_ARCH_TRACEHOOK
58 select HAVE_GENERIC_DMA_COHERENT if X86_32
59 select HAVE_EFFICIENT_UNALIGNED_ACCESS
60 select USER_STACKTRACE_SUPPORT
61 select HAVE_REGS_AND_STACK_ACCESS_API
62 select HAVE_DMA_API_DEBUG
63 select HAVE_KERNEL_GZIP
64 select HAVE_KERNEL_BZIP2
65 select HAVE_KERNEL_LZMA
66 select HAVE_KERNEL_XZ
67 select HAVE_KERNEL_LZO
68 select HAVE_HW_BREAKPOINT
69 select HAVE_MIXED_BREAKPOINTS_REGS
70 select PERF_EVENTS
71 select HAVE_PERF_EVENTS_NMI
72 select HAVE_PERF_REGS
73 select HAVE_PERF_USER_STACK_DUMP
74 select HAVE_DEBUG_KMEMLEAK
75 select ANON_INODES
76 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
77 select HAVE_CMPXCHG_LOCAL
78 select HAVE_CMPXCHG_DOUBLE
79 select HAVE_ARCH_KMEMCHECK
80 select HAVE_USER_RETURN_NOTIFIER
81 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
82 select HAVE_ARCH_JUMP_LABEL
83 select HAVE_TEXT_POKE_SMP
84 select HAVE_GENERIC_HARDIRQS
85 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
86 select SPARSE_IRQ
87 select GENERIC_FIND_FIRST_BIT
88 select GENERIC_IRQ_PROBE
89 select GENERIC_PENDING_IRQ if SMP
90 select GENERIC_IRQ_SHOW
91 select GENERIC_CLOCKEVENTS_MIN_ADJUST
92 select IRQ_FORCED_THREADING
93 select USE_GENERIC_SMP_HELPERS if SMP
94 select HAVE_BPF_JIT if X86_64
95 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
96 select CLKEVT_I8253
97 select ARCH_HAVE_NMI_SAFE_CMPXCHG
98 select GENERIC_IOMAP
99 select DCACHE_WORD_ACCESS
100 select GENERIC_SMP_IDLE_THREAD
101 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
102 select HAVE_ARCH_SECCOMP_FILTER
103 select BUILDTIME_EXTABLE_SORT
104 select GENERIC_CMOS_UPDATE
105 select CLOCKSOURCE_WATCHDOG
106 select GENERIC_CLOCKEVENTS
107 select ARCH_CLOCKSOURCE_DATA if X86_64
108 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
109 select GENERIC_TIME_VSYSCALL if X86_64
110 select KTIME_SCALAR if X86_32
111 select GENERIC_STRNCPY_FROM_USER
112 select GENERIC_STRNLEN_USER
113 select HAVE_CONTEXT_TRACKING if X86_64
114 select HAVE_IRQ_TIME_ACCOUNTING
115 select VIRT_TO_BUS
116 select MODULES_USE_ELF_REL if X86_32
117 select MODULES_USE_ELF_RELA if X86_64
118 select CLONE_BACKWARDS if X86_32
119 select ARCH_USE_BUILTIN_BSWAP
120 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
121 select OLD_SIGACTION if X86_32
122 select COMPAT_OLD_SIGACTION if IA32_EMULATION
123 select RTC_LIB
124
125 config INSTRUCTION_DECODER
126 def_bool y
127 depends on KPROBES || PERF_EVENTS || UPROBES
128
129 config OUTPUT_FORMAT
130 string
131 default "elf32-i386" if X86_32
132 default "elf64-x86-64" if X86_64
133
134 config ARCH_DEFCONFIG
135 string
136 default "arch/x86/configs/i386_defconfig" if X86_32
137 default "arch/x86/configs/x86_64_defconfig" if X86_64
138
139 config LOCKDEP_SUPPORT
140 def_bool y
141
142 config STACKTRACE_SUPPORT
143 def_bool y
144
145 config HAVE_LATENCYTOP_SUPPORT
146 def_bool y
147
148 config MMU
149 def_bool y
150
151 config SBUS
152 bool
153
154 config NEED_DMA_MAP_STATE
155 def_bool y
156 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
157
158 config NEED_SG_DMA_LENGTH
159 def_bool y
160
161 config GENERIC_ISA_DMA
162 def_bool y
163 depends on ISA_DMA_API
164
165 config GENERIC_BUG
166 def_bool y
167 depends on BUG
168 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
169
170 config GENERIC_BUG_RELATIVE_POINTERS
171 bool
172
173 config GENERIC_HWEIGHT
174 def_bool y
175
176 config ARCH_MAY_HAVE_PC_FDC
177 def_bool y
178 depends on ISA_DMA_API
179
180 config RWSEM_XCHGADD_ALGORITHM
181 def_bool y
182
183 config GENERIC_CALIBRATE_DELAY
184 def_bool y
185
186 config ARCH_HAS_CPU_RELAX
187 def_bool y
188
189 config ARCH_HAS_CACHE_LINE_SIZE
190 def_bool y
191
192 config ARCH_HAS_CPU_AUTOPROBE
193 def_bool y
194
195 config HAVE_SETUP_PER_CPU_AREA
196 def_bool y
197
198 config NEED_PER_CPU_EMBED_FIRST_CHUNK
199 def_bool y
200
201 config NEED_PER_CPU_PAGE_FIRST_CHUNK
202 def_bool y
203
204 config ARCH_HIBERNATION_POSSIBLE
205 def_bool y
206
207 config ARCH_SUSPEND_POSSIBLE
208 def_bool y
209
210 config ARCH_WANT_HUGE_PMD_SHARE
211 def_bool y
212
213 config ARCH_WANT_GENERAL_HUGETLB
214 def_bool y
215
216 config ZONE_DMA32
217 bool
218 default X86_64
219
220 config AUDIT_ARCH
221 bool
222 default X86_64
223
224 config ARCH_SUPPORTS_OPTIMIZED_INLINING
225 def_bool y
226
227 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
228 def_bool y
229
230 config HAVE_INTEL_TXT
231 def_bool y
232 depends on INTEL_IOMMU && ACPI
233
234 config X86_32_SMP
235 def_bool y
236 depends on X86_32 && SMP
237
238 config X86_64_SMP
239 def_bool y
240 depends on X86_64 && SMP
241
242 config X86_HT
243 def_bool y
244 depends on SMP
245
246 config X86_32_LAZY_GS
247 def_bool y
248 depends on X86_32 && !CC_STACKPROTECTOR
249
250 config ARCH_HWEIGHT_CFLAGS
251 string
252 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
253 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
254
255 config ARCH_CPU_PROBE_RELEASE
256 def_bool y
257 depends on HOTPLUG_CPU
258
259 config ARCH_SUPPORTS_UPROBES
260 def_bool y
261
262 source "init/Kconfig"
263 source "kernel/Kconfig.freezer"
264
265 menu "Processor type and features"
266
267 config ZONE_DMA
268 bool "DMA memory allocation support" if EXPERT
269 default y
270 help
271 DMA memory allocation support allows devices with less than 32-bit
272 addressing to allocate within the first 16MB of address space.
273 Disable if no such devices will be used.
274
275 If unsure, say Y.
276
277 config SMP
278 bool "Symmetric multi-processing support"
279 ---help---
280 This enables support for systems with more than one CPU. If you have
281 a system with only one CPU, like most personal computers, say N. If
282 you have a system with more than one CPU, say Y.
283
284 If you say N here, the kernel will run on single and multiprocessor
285 machines, but will use only one CPU of a multiprocessor machine. If
286 you say Y here, the kernel will run on many, but not all,
287 singleprocessor machines. On a singleprocessor machine, the kernel
288 will run faster if you say N here.
289
290 Note that if you say Y here and choose architecture "586" or
291 "Pentium" under "Processor family", the kernel will not work on 486
292 architectures. Similarly, multiprocessor kernels for the "PPro"
293 architecture may not work on all Pentium based boards.
294
295 People using multiprocessor machines who say Y here should also say
296 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
297 Management" code will be disabled if you say Y here.
298
299 See also <file:Documentation/x86/i386/IO-APIC.txt>,
300 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
301 <http://www.tldp.org/docs.html#howto>.
302
303 If you don't know what to do here, say N.
304
305 config X86_X2APIC
306 bool "Support x2apic"
307 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
308 ---help---
309 This enables x2apic support on CPUs that have this feature.
310
311 This allows 32-bit apic IDs (so it can support very large systems),
312 and accesses the local apic via MSRs not via mmio.
313
314 If you don't know what to do here, say N.
315
316 config X86_MPPARSE
317 bool "Enable MPS table" if ACPI || SFI
318 default y
319 depends on X86_LOCAL_APIC
320 ---help---
321 For old smp systems that do not have proper acpi support. Newer systems
322 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
323
324 config X86_BIGSMP
325 bool "Support for big SMP systems with more than 8 CPUs"
326 depends on X86_32 && SMP
327 ---help---
328 This option is needed for the systems that have more than 8 CPUs
329
330 config GOLDFISH
331 def_bool y
332 depends on X86_GOLDFISH
333
334 if X86_32
335 config X86_EXTENDED_PLATFORM
336 bool "Support for extended (non-PC) x86 platforms"
337 default y
338 ---help---
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
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 Goldfish (Android emulator)
346 AMD Elan
347 NUMAQ (IBM/Sequent)
348 RDC R-321x SoC
349 SGI 320/540 (Visual Workstation)
350 STA2X11-based (e.g. Northville)
351 Summit/EXA (IBM x440)
352 Unisys ES7000 IA32 series
353 Moorestown MID devices
354
355 If you have one of these systems, or if you want to build a
356 generic distribution kernel, say Y here - otherwise say N.
357 endif
358
359 if X86_64
360 config X86_EXTENDED_PLATFORM
361 bool "Support for extended (non-PC) x86 platforms"
362 default y
363 ---help---
364 If you disable this option then the kernel will only support
365 standard PC platforms. (which covers the vast majority of
366 systems out there.)
367
368 If you enable this option then you'll be able to select support
369 for the following (non-PC) 64 bit x86 platforms:
370 Numascale NumaChip
371 ScaleMP vSMP
372 SGI Ultraviolet
373
374 If you have one of these systems, or if you want to build a
375 generic distribution kernel, say Y here - otherwise say N.
376 endif
377 # This is an alphabetically sorted list of 64 bit extended platforms
378 # Please maintain the alphabetic order if and when there are additions
379 config X86_NUMACHIP
380 bool "Numascale NumaChip"
381 depends on X86_64
382 depends on X86_EXTENDED_PLATFORM
383 depends on NUMA
384 depends on SMP
385 depends on X86_X2APIC
386 depends on PCI_MMCONFIG
387 ---help---
388 Adds support for Numascale NumaChip large-SMP systems. Needed to
389 enable more than ~168 cores.
390 If you don't have one of these, you should say N here.
391
392 config X86_VSMP
393 bool "ScaleMP vSMP"
394 select HYPERVISOR_GUEST
395 select PARAVIRT
396 depends on X86_64 && PCI
397 depends on X86_EXTENDED_PLATFORM
398 depends on SMP
399 ---help---
400 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
401 supposed to run on these EM64T-based machines. Only choose this option
402 if you have one of these machines.
403
404 config X86_UV
405 bool "SGI Ultraviolet"
406 depends on X86_64
407 depends on X86_EXTENDED_PLATFORM
408 depends on NUMA
409 depends on X86_X2APIC
410 ---help---
411 This option is needed in order to support SGI Ultraviolet systems.
412 If you don't have one of these, you should say N here.
413
414 # Following is an alphabetically sorted list of 32 bit extended platforms
415 # Please maintain the alphabetic order if and when there are additions
416
417 config X86_GOLDFISH
418 bool "Goldfish (Virtual Platform)"
419 depends on X86_32
420 depends on X86_EXTENDED_PLATFORM
421 ---help---
422 Enable support for the Goldfish virtual platform used primarily
423 for Android development. Unless you are building for the Android
424 Goldfish emulator say N here.
425
426 config X86_INTEL_CE
427 bool "CE4100 TV platform"
428 depends on PCI
429 depends on PCI_GODIRECT
430 depends on X86_32
431 depends on X86_EXTENDED_PLATFORM
432 select X86_REBOOTFIXUPS
433 select OF
434 select OF_EARLY_FLATTREE
435 select IRQ_DOMAIN
436 ---help---
437 Select for the Intel CE media processor (CE4100) SOC.
438 This option compiles in support for the CE4100 SOC for settop
439 boxes and media devices.
440
441 config X86_WANT_INTEL_MID
442 bool "Intel MID platform support"
443 depends on X86_32
444 depends on X86_EXTENDED_PLATFORM
445 ---help---
446 Select to build a kernel capable of supporting Intel MID platform
447 systems which do not have the PCI legacy interfaces (Moorestown,
448 Medfield). If you are building for a PC class system say N here.
449
450 if X86_WANT_INTEL_MID
451
452 config X86_INTEL_MID
453 bool
454
455 config X86_MDFLD
456 bool "Medfield MID platform"
457 depends on PCI
458 depends on PCI_GOANY
459 depends on X86_IO_APIC
460 select X86_INTEL_MID
461 select SFI
462 select DW_APB_TIMER
463 select APB_TIMER
464 select I2C
465 select SPI
466 select INTEL_SCU_IPC
467 select X86_PLATFORM_DEVICES
468 select MFD_INTEL_MSIC
469 ---help---
470 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
471 Internet Device(MID) platform.
472 Unlike standard x86 PCs, Medfield does not have many legacy devices
473 nor standard legacy replacement devices/features. e.g. Medfield does
474 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
475
476 endif
477
478 config X86_INTEL_LPSS
479 bool "Intel Low Power Subsystem Support"
480 depends on ACPI
481 select COMMON_CLK
482 ---help---
483 Select to build support for Intel Low Power Subsystem such as
484 found on Intel Lynxpoint PCH. Selecting this option enables
485 things like clock tree (common clock framework) which are needed
486 by the LPSS peripheral drivers.
487
488 config X86_RDC321X
489 bool "RDC R-321x SoC"
490 depends on X86_32
491 depends on X86_EXTENDED_PLATFORM
492 select M486
493 select X86_REBOOTFIXUPS
494 ---help---
495 This option is needed for RDC R-321x system-on-chip, also known
496 as R-8610-(G).
497 If you don't have one of these chips, you should say N here.
498
499 config X86_32_NON_STANDARD
500 bool "Support non-standard 32-bit SMP architectures"
501 depends on X86_32 && SMP
502 depends on X86_EXTENDED_PLATFORM
503 ---help---
504 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
505 STA2X11, default subarchitectures. It is intended for a generic
506 binary kernel. If you select them all, kernel will probe it
507 one by one and will fallback to default.
508
509 # Alphabetically sorted list of Non standard 32 bit platforms
510
511 config X86_NUMAQ
512 bool "NUMAQ (IBM/Sequent)"
513 depends on X86_32_NON_STANDARD
514 depends on PCI
515 select NUMA
516 select X86_MPPARSE
517 ---help---
518 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
519 NUMA multiquad box. This changes the way that processors are
520 bootstrapped, and uses Clustered Logical APIC addressing mode instead
521 of Flat Logical. You will need a new lynxer.elf file to flash your
522 firmware with - send email to <Martin.Bligh@us.ibm.com>.
523
524 config X86_SUPPORTS_MEMORY_FAILURE
525 def_bool y
526 # MCE code calls memory_failure():
527 depends on X86_MCE
528 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
529 depends on !X86_NUMAQ
530 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
531 depends on X86_64 || !SPARSEMEM
532 select ARCH_SUPPORTS_MEMORY_FAILURE
533
534 config X86_VISWS
535 bool "SGI 320/540 (Visual Workstation)"
536 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
537 depends on X86_32_NON_STANDARD
538 ---help---
539 The SGI Visual Workstation series is an IA32-based workstation
540 based on SGI systems chips with some legacy PC hardware attached.
541
542 Say Y here to create a kernel to run on the SGI 320 or 540.
543
544 A kernel compiled for the Visual Workstation will run on general
545 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
546
547 config STA2X11
548 bool "STA2X11 Companion Chip Support"
549 depends on X86_32_NON_STANDARD && PCI
550 select X86_DEV_DMA_OPS
551 select X86_DMA_REMAP
552 select SWIOTLB
553 select MFD_STA2X11
554 select ARCH_REQUIRE_GPIOLIB
555 default n
556 ---help---
557 This adds support for boards based on the STA2X11 IO-Hub,
558 a.k.a. "ConneXt". The chip is used in place of the standard
559 PC chipset, so all "standard" peripherals are missing. If this
560 option is selected the kernel will still be able to boot on
561 standard PC machines.
562
563 config X86_SUMMIT
564 bool "Summit/EXA (IBM x440)"
565 depends on X86_32_NON_STANDARD
566 ---help---
567 This option is needed for IBM systems that use the Summit/EXA chipset.
568 In particular, it is needed for the x440.
569
570 config X86_ES7000
571 bool "Unisys ES7000 IA32 series"
572 depends on X86_32_NON_STANDARD && X86_BIGSMP
573 ---help---
574 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
575 supposed to run on an IA32-based Unisys ES7000 system.
576
577 config X86_32_IRIS
578 tristate "Eurobraille/Iris poweroff module"
579 depends on X86_32
580 ---help---
581 The Iris machines from EuroBraille do not have APM or ACPI support
582 to shut themselves down properly. A special I/O sequence is
583 needed to do so, which is what this module does at
584 kernel shutdown.
585
586 This is only for Iris machines from EuroBraille.
587
588 If unused, say N.
589
590 config SCHED_OMIT_FRAME_POINTER
591 def_bool y
592 prompt "Single-depth WCHAN output"
593 depends on X86
594 ---help---
595 Calculate simpler /proc/<PID>/wchan values. If this option
596 is disabled then wchan values will recurse back to the
597 caller function. This provides more accurate wchan values,
598 at the expense of slightly more scheduling overhead.
599
600 If in doubt, say "Y".
601
602 menuconfig HYPERVISOR_GUEST
603 bool "Linux guest support"
604 ---help---
605 Say Y here to enable options for running Linux under various hyper-
606 visors. This option enables basic hypervisor detection and platform
607 setup.
608
609 If you say N, all options in this submenu will be skipped and
610 disabled, and Linux guest support won't be built in.
611
612 if HYPERVISOR_GUEST
613
614 config PARAVIRT
615 bool "Enable paravirtualization code"
616 ---help---
617 This changes the kernel so it can modify itself when it is run
618 under a hypervisor, potentially improving performance significantly
619 over full virtualization. However, when run without a hypervisor
620 the kernel is theoretically slower and slightly larger.
621
622 config PARAVIRT_DEBUG
623 bool "paravirt-ops debugging"
624 depends on PARAVIRT && DEBUG_KERNEL
625 ---help---
626 Enable to debug paravirt_ops internals. Specifically, BUG if
627 a paravirt_op is missing when it is called.
628
629 config PARAVIRT_SPINLOCKS
630 bool "Paravirtualization layer for spinlocks"
631 depends on PARAVIRT && SMP
632 ---help---
633 Paravirtualized spinlocks allow a pvops backend to replace the
634 spinlock implementation with something virtualization-friendly
635 (for example, block the virtual CPU rather than spinning).
636
637 Unfortunately the downside is an up to 5% performance hit on
638 native kernels, with various workloads.
639
640 If you are unsure how to answer this question, answer N.
641
642 source "arch/x86/xen/Kconfig"
643
644 config KVM_GUEST
645 bool "KVM Guest support (including kvmclock)"
646 depends on PARAVIRT
647 select PARAVIRT_CLOCK
648 default y
649 ---help---
650 This option enables various optimizations for running under the KVM
651 hypervisor. It includes a paravirtualized clock, so that instead
652 of relying on a PIT (or probably other) emulation by the
653 underlying device model, the host provides the guest with
654 timing infrastructure such as time of day, and system time
655
656 source "arch/x86/lguest/Kconfig"
657
658 config PARAVIRT_TIME_ACCOUNTING
659 bool "Paravirtual steal time accounting"
660 depends on PARAVIRT
661 default n
662 ---help---
663 Select this option to enable fine granularity task steal time
664 accounting. Time spent executing other tasks in parallel with
665 the current vCPU is discounted from the vCPU power. To account for
666 that, there can be a small performance impact.
667
668 If in doubt, say N here.
669
670 config PARAVIRT_CLOCK
671 bool
672
673 endif #HYPERVISOR_GUEST
674
675 config NO_BOOTMEM
676 def_bool y
677
678 config MEMTEST
679 bool "Memtest"
680 ---help---
681 This option adds a kernel parameter 'memtest', which allows memtest
682 to be set.
683 memtest=0, mean disabled; -- default
684 memtest=1, mean do 1 test pattern;
685 ...
686 memtest=4, mean do 4 test patterns.
687 If you are unsure how to answer this question, answer N.
688
689 config X86_SUMMIT_NUMA
690 def_bool y
691 depends on X86_32 && NUMA && X86_32_NON_STANDARD
692
693 config X86_CYCLONE_TIMER
694 def_bool y
695 depends on X86_SUMMIT
696
697 source "arch/x86/Kconfig.cpu"
698
699 config HPET_TIMER
700 def_bool X86_64
701 prompt "HPET Timer Support" if X86_32
702 ---help---
703 Use the IA-PC HPET (High Precision Event Timer) to manage
704 time in preference to the PIT and RTC, if a HPET is
705 present.
706 HPET is the next generation timer replacing legacy 8254s.
707 The HPET provides a stable time base on SMP
708 systems, unlike the TSC, but it is more expensive to access,
709 as it is off-chip. You can find the HPET spec at
710 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
711
712 You can safely choose Y here. However, HPET will only be
713 activated if the platform and the BIOS support this feature.
714 Otherwise the 8254 will be used for timing services.
715
716 Choose N to continue using the legacy 8254 timer.
717
718 config HPET_EMULATE_RTC
719 def_bool y
720 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
721
722 config APB_TIMER
723 def_bool y if X86_INTEL_MID
724 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
725 select DW_APB_TIMER
726 depends on X86_INTEL_MID && SFI
727 help
728 APB timer is the replacement for 8254, HPET on X86 MID platforms.
729 The APBT provides a stable time base on SMP
730 systems, unlike the TSC, but it is more expensive to access,
731 as it is off-chip. APB timers are always running regardless of CPU
732 C states, they are used as per CPU clockevent device when possible.
733
734 # Mark as expert because too many people got it wrong.
735 # The code disables itself when not needed.
736 config DMI
737 default y
738 bool "Enable DMI scanning" if EXPERT
739 ---help---
740 Enabled scanning of DMI to identify machine quirks. Say Y
741 here unless you have verified that your setup is not
742 affected by entries in the DMI blacklist. Required by PNP
743 BIOS code.
744
745 config GART_IOMMU
746 bool "GART IOMMU support" if EXPERT
747 default y
748 select SWIOTLB
749 depends on X86_64 && PCI && AMD_NB
750 ---help---
751 Support for full DMA access of devices with 32bit memory access only
752 on systems with more than 3GB. This is usually needed for USB,
753 sound, many IDE/SATA chipsets and some other devices.
754 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
755 based hardware IOMMU and a software bounce buffer based IOMMU used
756 on Intel systems and as fallback.
757 The code is only active when needed (enough memory and limited
758 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
759 too.
760
761 config CALGARY_IOMMU
762 bool "IBM Calgary IOMMU support"
763 select SWIOTLB
764 depends on X86_64 && PCI
765 ---help---
766 Support for hardware IOMMUs in IBM's xSeries x366 and x460
767 systems. Needed to run systems with more than 3GB of memory
768 properly with 32-bit PCI devices that do not support DAC
769 (Double Address Cycle). Calgary also supports bus level
770 isolation, where all DMAs pass through the IOMMU. This
771 prevents them from going anywhere except their intended
772 destination. This catches hard-to-find kernel bugs and
773 mis-behaving drivers and devices that do not use the DMA-API
774 properly to set up their DMA buffers. The IOMMU can be
775 turned off at boot time with the iommu=off parameter.
776 Normally the kernel will make the right choice by itself.
777 If unsure, say Y.
778
779 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
780 def_bool y
781 prompt "Should Calgary be enabled by default?"
782 depends on CALGARY_IOMMU
783 ---help---
784 Should Calgary be enabled by default? if you choose 'y', Calgary
785 will be used (if it exists). If you choose 'n', Calgary will not be
786 used even if it exists. If you choose 'n' and would like to use
787 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
788 If unsure, say Y.
789
790 # need this always selected by IOMMU for the VIA workaround
791 config SWIOTLB
792 def_bool y if X86_64
793 ---help---
794 Support for software bounce buffers used on x86-64 systems
795 which don't have a hardware IOMMU. Using this PCI devices
796 which can only access 32-bits of memory can be used on systems
797 with more than 3 GB of memory.
798 If unsure, say Y.
799
800 config IOMMU_HELPER
801 def_bool y
802 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
803
804 config MAXSMP
805 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
806 depends on X86_64 && SMP && DEBUG_KERNEL
807 select CPUMASK_OFFSTACK
808 ---help---
809 Enable maximum number of CPUS and NUMA Nodes for this architecture.
810 If unsure, say N.
811
812 config NR_CPUS
813 int "Maximum number of CPUs" if SMP && !MAXSMP
814 range 2 8 if SMP && X86_32 && !X86_BIGSMP
815 range 2 512 if SMP && !MAXSMP
816 default "1" if !SMP
817 default "4096" if MAXSMP
818 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
819 default "8" if SMP
820 ---help---
821 This allows you to specify the maximum number of CPUs which this
822 kernel will support. The maximum supported value is 512 and the
823 minimum value which makes sense is 2.
824
825 This is purely to save memory - each supported CPU adds
826 approximately eight kilobytes to the kernel image.
827
828 config SCHED_SMT
829 bool "SMT (Hyperthreading) scheduler support"
830 depends on X86_HT
831 ---help---
832 SMT scheduler support improves the CPU scheduler's decision making
833 when dealing with Intel Pentium 4 chips with HyperThreading at a
834 cost of slightly increased overhead in some places. If unsure say
835 N here.
836
837 config SCHED_MC
838 def_bool y
839 prompt "Multi-core scheduler support"
840 depends on X86_HT
841 ---help---
842 Multi-core scheduler support improves the CPU scheduler's decision
843 making when dealing with multi-core CPU chips at a cost of slightly
844 increased overhead in some places. If unsure say N here.
845
846 source "kernel/Kconfig.preempt"
847
848 config X86_UP_APIC
849 bool "Local APIC support on uniprocessors"
850 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
851 ---help---
852 A local APIC (Advanced Programmable Interrupt Controller) is an
853 integrated interrupt controller in the CPU. If you have a single-CPU
854 system which has a processor with a local APIC, you can say Y here to
855 enable and use it. If you say Y here even though your machine doesn't
856 have a local APIC, then the kernel will still run with no slowdown at
857 all. The local APIC supports CPU-generated self-interrupts (timer,
858 performance counters), and the NMI watchdog which detects hard
859 lockups.
860
861 config X86_UP_IOAPIC
862 bool "IO-APIC support on uniprocessors"
863 depends on X86_UP_APIC
864 ---help---
865 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
866 SMP-capable replacement for PC-style interrupt controllers. Most
867 SMP systems and many recent uniprocessor systems have one.
868
869 If you have a single-CPU system with an IO-APIC, you can say Y here
870 to use it. If you say Y here even though your machine doesn't have
871 an IO-APIC, then the kernel will still run with no slowdown at all.
872
873 config X86_LOCAL_APIC
874 def_bool y
875 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
876
877 config X86_IO_APIC
878 def_bool y
879 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
880
881 config X86_VISWS_APIC
882 def_bool y
883 depends on X86_32 && X86_VISWS
884
885 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
886 bool "Reroute for broken boot IRQs"
887 depends on X86_IO_APIC
888 ---help---
889 This option enables a workaround that fixes a source of
890 spurious interrupts. This is recommended when threaded
891 interrupt handling is used on systems where the generation of
892 superfluous "boot interrupts" cannot be disabled.
893
894 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
895 entry in the chipset's IO-APIC is masked (as, e.g. the RT
896 kernel does during interrupt handling). On chipsets where this
897 boot IRQ generation cannot be disabled, this workaround keeps
898 the original IRQ line masked so that only the equivalent "boot
899 IRQ" is delivered to the CPUs. The workaround also tells the
900 kernel to set up the IRQ handler on the boot IRQ line. In this
901 way only one interrupt is delivered to the kernel. Otherwise
902 the spurious second interrupt may cause the kernel to bring
903 down (vital) interrupt lines.
904
905 Only affects "broken" chipsets. Interrupt sharing may be
906 increased on these systems.
907
908 config X86_MCE
909 bool "Machine Check / overheating reporting"
910 default y
911 ---help---
912 Machine Check support allows the processor to notify the
913 kernel if it detects a problem (e.g. overheating, data corruption).
914 The action the kernel takes depends on the severity of the problem,
915 ranging from warning messages to halting the machine.
916
917 config X86_MCE_INTEL
918 def_bool y
919 prompt "Intel MCE features"
920 depends on X86_MCE && X86_LOCAL_APIC
921 ---help---
922 Additional support for intel specific MCE features such as
923 the thermal monitor.
924
925 config X86_MCE_AMD
926 def_bool y
927 prompt "AMD MCE features"
928 depends on X86_MCE && X86_LOCAL_APIC
929 ---help---
930 Additional support for AMD specific MCE features such as
931 the DRAM Error Threshold.
932
933 config X86_ANCIENT_MCE
934 bool "Support for old Pentium 5 / WinChip machine checks"
935 depends on X86_32 && X86_MCE
936 ---help---
937 Include support for machine check handling on old Pentium 5 or WinChip
938 systems. These typically need to be enabled explicitely on the command
939 line.
940
941 config X86_MCE_THRESHOLD
942 depends on X86_MCE_AMD || X86_MCE_INTEL
943 def_bool y
944
945 config X86_MCE_INJECT
946 depends on X86_MCE
947 tristate "Machine check injector support"
948 ---help---
949 Provide support for injecting machine checks for testing purposes.
950 If you don't know what a machine check is and you don't do kernel
951 QA it is safe to say n.
952
953 config X86_THERMAL_VECTOR
954 def_bool y
955 depends on X86_MCE_INTEL
956
957 config VM86
958 bool "Enable VM86 support" if EXPERT
959 default y
960 depends on X86_32
961 ---help---
962 This option is required by programs like DOSEMU to run 16-bit legacy
963 code on X86 processors. It also may be needed by software like
964 XFree86 to initialize some video cards via BIOS. Disabling this
965 option saves about 6k.
966
967 config TOSHIBA
968 tristate "Toshiba Laptop support"
969 depends on X86_32
970 ---help---
971 This adds a driver to safely access the System Management Mode of
972 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
973 not work on models with a Phoenix BIOS. The System Management Mode
974 is used to set the BIOS and power saving options on Toshiba portables.
975
976 For information on utilities to make use of this driver see the
977 Toshiba Linux utilities web site at:
978 <http://www.buzzard.org.uk/toshiba/>.
979
980 Say Y if you intend to run this kernel on a Toshiba portable.
981 Say N otherwise.
982
983 config I8K
984 tristate "Dell laptop support"
985 select HWMON
986 ---help---
987 This adds a driver to safely access the System Management Mode
988 of the CPU on the Dell Inspiron 8000. The System Management Mode
989 is used to read cpu temperature and cooling fan status and to
990 control the fans on the I8K portables.
991
992 This driver has been tested only on the Inspiron 8000 but it may
993 also work with other Dell laptops. You can force loading on other
994 models by passing the parameter `force=1' to the module. Use at
995 your own risk.
996
997 For information on utilities to make use of this driver see the
998 I8K Linux utilities web site at:
999 <http://people.debian.org/~dz/i8k/>
1000
1001 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1002 Say N otherwise.
1003
1004 config X86_REBOOTFIXUPS
1005 bool "Enable X86 board specific fixups for reboot"
1006 depends on X86_32
1007 ---help---
1008 This enables chipset and/or board specific fixups to be done
1009 in order to get reboot to work correctly. This is only needed on
1010 some combinations of hardware and BIOS. The symptom, for which
1011 this config is intended, is when reboot ends with a stalled/hung
1012 system.
1013
1014 Currently, the only fixup is for the Geode machines using
1015 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1016
1017 Say Y if you want to enable the fixup. Currently, it's safe to
1018 enable this option even if you don't need it.
1019 Say N otherwise.
1020
1021 config MICROCODE
1022 tristate "CPU microcode loading support"
1023 select FW_LOADER
1024 ---help---
1025
1026 If you say Y here, you will be able to update the microcode on
1027 certain Intel and AMD processors. The Intel support is for the
1028 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1029 Xeon etc. The AMD support is for families 0x10 and later. You will
1030 obviously need the actual microcode binary data itself which is not
1031 shipped with the Linux kernel.
1032
1033 This option selects the general module only, you need to select
1034 at least one vendor specific module as well.
1035
1036 To compile this driver as a module, choose M here: the module
1037 will be called microcode.
1038
1039 config MICROCODE_INTEL
1040 bool "Intel microcode loading support"
1041 depends on MICROCODE
1042 default MICROCODE
1043 select FW_LOADER
1044 ---help---
1045 This options enables microcode patch loading support for Intel
1046 processors.
1047
1048 For latest news and information on obtaining all the required
1049 Intel ingredients for this driver, check:
1050 <http://www.urbanmyth.org/microcode/>.
1051
1052 config MICROCODE_AMD
1053 bool "AMD microcode loading support"
1054 depends on MICROCODE
1055 select FW_LOADER
1056 ---help---
1057 If you select this option, microcode patch loading support for AMD
1058 processors will be enabled.
1059
1060 config MICROCODE_OLD_INTERFACE
1061 def_bool y
1062 depends on MICROCODE
1063
1064 config MICROCODE_INTEL_LIB
1065 def_bool y
1066 depends on MICROCODE_INTEL
1067
1068 config MICROCODE_INTEL_EARLY
1069 def_bool n
1070
1071 config MICROCODE_AMD_EARLY
1072 def_bool n
1073
1074 config MICROCODE_EARLY
1075 bool "Early load microcode"
1076 depends on MICROCODE=y && BLK_DEV_INITRD
1077 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1078 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1079 default y
1080 help
1081 This option provides functionality to read additional microcode data
1082 at the beginning of initrd image. The data tells kernel to load
1083 microcode to CPU's as early as possible. No functional change if no
1084 microcode data is glued to the initrd, therefore it's safe to say Y.
1085
1086 config X86_MSR
1087 tristate "/dev/cpu/*/msr - Model-specific register support"
1088 ---help---
1089 This device gives privileged processes access to the x86
1090 Model-Specific Registers (MSRs). It is a character device with
1091 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1092 MSR accesses are directed to a specific CPU on multi-processor
1093 systems.
1094
1095 config X86_CPUID
1096 tristate "/dev/cpu/*/cpuid - CPU information support"
1097 ---help---
1098 This device gives processes access to the x86 CPUID instruction to
1099 be executed on a specific processor. It is a character device
1100 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1101 /dev/cpu/31/cpuid.
1102
1103 choice
1104 prompt "High Memory Support"
1105 default HIGHMEM64G if X86_NUMAQ
1106 default HIGHMEM4G
1107 depends on X86_32
1108
1109 config NOHIGHMEM
1110 bool "off"
1111 depends on !X86_NUMAQ
1112 ---help---
1113 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1114 However, the address space of 32-bit x86 processors is only 4
1115 Gigabytes large. That means that, if you have a large amount of
1116 physical memory, not all of it can be "permanently mapped" by the
1117 kernel. The physical memory that's not permanently mapped is called
1118 "high memory".
1119
1120 If you are compiling a kernel which will never run on a machine with
1121 more than 1 Gigabyte total physical RAM, answer "off" here (default
1122 choice and suitable for most users). This will result in a "3GB/1GB"
1123 split: 3GB are mapped so that each process sees a 3GB virtual memory
1124 space and the remaining part of the 4GB virtual memory space is used
1125 by the kernel to permanently map as much physical memory as
1126 possible.
1127
1128 If the machine has between 1 and 4 Gigabytes physical RAM, then
1129 answer "4GB" here.
1130
1131 If more than 4 Gigabytes is used then answer "64GB" here. This
1132 selection turns Intel PAE (Physical Address Extension) mode on.
1133 PAE implements 3-level paging on IA32 processors. PAE is fully
1134 supported by Linux, PAE mode is implemented on all recent Intel
1135 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1136 then the kernel will not boot on CPUs that don't support PAE!
1137
1138 The actual amount of total physical memory will either be
1139 auto detected or can be forced by using a kernel command line option
1140 such as "mem=256M". (Try "man bootparam" or see the documentation of
1141 your boot loader (lilo or loadlin) about how to pass options to the
1142 kernel at boot time.)
1143
1144 If unsure, say "off".
1145
1146 config HIGHMEM4G
1147 bool "4GB"
1148 depends on !X86_NUMAQ
1149 ---help---
1150 Select this if you have a 32-bit processor and between 1 and 4
1151 gigabytes of physical RAM.
1152
1153 config HIGHMEM64G
1154 bool "64GB"
1155 depends on !M486
1156 select X86_PAE
1157 ---help---
1158 Select this if you have a 32-bit processor and more than 4
1159 gigabytes of physical RAM.
1160
1161 endchoice
1162
1163 choice
1164 prompt "Memory split" if EXPERT
1165 default VMSPLIT_3G
1166 depends on X86_32
1167 ---help---
1168 Select the desired split between kernel and user memory.
1169
1170 If the address range available to the kernel is less than the
1171 physical memory installed, the remaining memory will be available
1172 as "high memory". Accessing high memory is a little more costly
1173 than low memory, as it needs to be mapped into the kernel first.
1174 Note that increasing the kernel address space limits the range
1175 available to user programs, making the address space there
1176 tighter. Selecting anything other than the default 3G/1G split
1177 will also likely make your kernel incompatible with binary-only
1178 kernel modules.
1179
1180 If you are not absolutely sure what you are doing, leave this
1181 option alone!
1182
1183 config VMSPLIT_3G
1184 bool "3G/1G user/kernel split"
1185 config VMSPLIT_3G_OPT
1186 depends on !X86_PAE
1187 bool "3G/1G user/kernel split (for full 1G low memory)"
1188 config VMSPLIT_2G
1189 bool "2G/2G user/kernel split"
1190 config VMSPLIT_2G_OPT
1191 depends on !X86_PAE
1192 bool "2G/2G user/kernel split (for full 2G low memory)"
1193 config VMSPLIT_1G
1194 bool "1G/3G user/kernel split"
1195 endchoice
1196
1197 config PAGE_OFFSET
1198 hex
1199 default 0xB0000000 if VMSPLIT_3G_OPT
1200 default 0x80000000 if VMSPLIT_2G
1201 default 0x78000000 if VMSPLIT_2G_OPT
1202 default 0x40000000 if VMSPLIT_1G
1203 default 0xC0000000
1204 depends on X86_32
1205
1206 config HIGHMEM
1207 def_bool y
1208 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1209
1210 config X86_PAE
1211 bool "PAE (Physical Address Extension) Support"
1212 depends on X86_32 && !HIGHMEM4G
1213 ---help---
1214 PAE is required for NX support, and furthermore enables
1215 larger swapspace support for non-overcommit purposes. It
1216 has the cost of more pagetable lookup overhead, and also
1217 consumes more pagetable space per process.
1218
1219 config ARCH_PHYS_ADDR_T_64BIT
1220 def_bool y
1221 depends on X86_64 || X86_PAE
1222
1223 config ARCH_DMA_ADDR_T_64BIT
1224 def_bool y
1225 depends on X86_64 || HIGHMEM64G
1226
1227 config DIRECT_GBPAGES
1228 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1229 default y
1230 depends on X86_64
1231 ---help---
1232 Allow the kernel linear mapping to use 1GB pages on CPUs that
1233 support it. This can improve the kernel's performance a tiny bit by
1234 reducing TLB pressure. If in doubt, say "Y".
1235
1236 # Common NUMA Features
1237 config NUMA
1238 bool "Numa Memory Allocation and Scheduler Support"
1239 depends on SMP
1240 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1241 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1242 ---help---
1243 Enable NUMA (Non Uniform Memory Access) support.
1244
1245 The kernel will try to allocate memory used by a CPU on the
1246 local memory controller of the CPU and add some more
1247 NUMA awareness to the kernel.
1248
1249 For 64-bit this is recommended if the system is Intel Core i7
1250 (or later), AMD Opteron, or EM64T NUMA.
1251
1252 For 32-bit this is only needed on (rare) 32-bit-only platforms
1253 that support NUMA topologies, such as NUMAQ / Summit, or if you
1254 boot a 32-bit kernel on a 64-bit NUMA platform.
1255
1256 Otherwise, you should say N.
1257
1258 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1259 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1260
1261 config AMD_NUMA
1262 def_bool y
1263 prompt "Old style AMD Opteron NUMA detection"
1264 depends on X86_64 && NUMA && PCI
1265 ---help---
1266 Enable AMD NUMA node topology detection. You should say Y here if
1267 you have a multi processor AMD system. This uses an old method to
1268 read the NUMA configuration directly from the builtin Northbridge
1269 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1270 which also takes priority if both are compiled in.
1271
1272 config X86_64_ACPI_NUMA
1273 def_bool y
1274 prompt "ACPI NUMA detection"
1275 depends on X86_64 && NUMA && ACPI && PCI
1276 select ACPI_NUMA
1277 ---help---
1278 Enable ACPI SRAT based node topology detection.
1279
1280 # Some NUMA nodes have memory ranges that span
1281 # other nodes. Even though a pfn is valid and
1282 # between a node's start and end pfns, it may not
1283 # reside on that node. See memmap_init_zone()
1284 # for details.
1285 config NODES_SPAN_OTHER_NODES
1286 def_bool y
1287 depends on X86_64_ACPI_NUMA
1288
1289 config NUMA_EMU
1290 bool "NUMA emulation"
1291 depends on NUMA
1292 ---help---
1293 Enable NUMA emulation. A flat machine will be split
1294 into virtual nodes when booted with "numa=fake=N", where N is the
1295 number of nodes. This is only useful for debugging.
1296
1297 config NODES_SHIFT
1298 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1299 range 1 10
1300 default "10" if MAXSMP
1301 default "6" if X86_64
1302 default "4" if X86_NUMAQ
1303 default "3"
1304 depends on NEED_MULTIPLE_NODES
1305 ---help---
1306 Specify the maximum number of NUMA Nodes available on the target
1307 system. Increases memory reserved to accommodate various tables.
1308
1309 config ARCH_HAVE_MEMORY_PRESENT
1310 def_bool y
1311 depends on X86_32 && DISCONTIGMEM
1312
1313 config NEED_NODE_MEMMAP_SIZE
1314 def_bool y
1315 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1316
1317 config ARCH_FLATMEM_ENABLE
1318 def_bool y
1319 depends on X86_32 && !NUMA
1320
1321 config ARCH_DISCONTIGMEM_ENABLE
1322 def_bool y
1323 depends on NUMA && X86_32
1324
1325 config ARCH_DISCONTIGMEM_DEFAULT
1326 def_bool y
1327 depends on NUMA && X86_32
1328
1329 config ARCH_SPARSEMEM_ENABLE
1330 def_bool y
1331 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1332 select SPARSEMEM_STATIC if X86_32
1333 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1334
1335 config ARCH_SPARSEMEM_DEFAULT
1336 def_bool y
1337 depends on X86_64
1338
1339 config ARCH_SELECT_MEMORY_MODEL
1340 def_bool y
1341 depends on ARCH_SPARSEMEM_ENABLE
1342
1343 config ARCH_MEMORY_PROBE
1344 def_bool y
1345 depends on X86_64 && MEMORY_HOTPLUG
1346
1347 config ARCH_PROC_KCORE_TEXT
1348 def_bool y
1349 depends on X86_64 && PROC_KCORE
1350
1351 config ILLEGAL_POINTER_VALUE
1352 hex
1353 default 0 if X86_32
1354 default 0xdead000000000000 if X86_64
1355
1356 source "mm/Kconfig"
1357
1358 config HIGHPTE
1359 bool "Allocate 3rd-level pagetables from highmem"
1360 depends on HIGHMEM
1361 ---help---
1362 The VM uses one page table entry for each page of physical memory.
1363 For systems with a lot of RAM, this can be wasteful of precious
1364 low memory. Setting this option will put user-space page table
1365 entries in high memory.
1366
1367 config X86_CHECK_BIOS_CORRUPTION
1368 bool "Check for low memory corruption"
1369 ---help---
1370 Periodically check for memory corruption in low memory, which
1371 is suspected to be caused by BIOS. Even when enabled in the
1372 configuration, it is disabled at runtime. Enable it by
1373 setting "memory_corruption_check=1" on the kernel command
1374 line. By default it scans the low 64k of memory every 60
1375 seconds; see the memory_corruption_check_size and
1376 memory_corruption_check_period parameters in
1377 Documentation/kernel-parameters.txt to adjust this.
1378
1379 When enabled with the default parameters, this option has
1380 almost no overhead, as it reserves a relatively small amount
1381 of memory and scans it infrequently. It both detects corruption
1382 and prevents it from affecting the running system.
1383
1384 It is, however, intended as a diagnostic tool; if repeatable
1385 BIOS-originated corruption always affects the same memory,
1386 you can use memmap= to prevent the kernel from using that
1387 memory.
1388
1389 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1390 bool "Set the default setting of memory_corruption_check"
1391 depends on X86_CHECK_BIOS_CORRUPTION
1392 default y
1393 ---help---
1394 Set whether the default state of memory_corruption_check is
1395 on or off.
1396
1397 config X86_RESERVE_LOW
1398 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1399 default 64
1400 range 4 640
1401 ---help---
1402 Specify the amount of low memory to reserve for the BIOS.
1403
1404 The first page contains BIOS data structures that the kernel
1405 must not use, so that page must always be reserved.
1406
1407 By default we reserve the first 64K of physical RAM, as a
1408 number of BIOSes are known to corrupt that memory range
1409 during events such as suspend/resume or monitor cable
1410 insertion, so it must not be used by the kernel.
1411
1412 You can set this to 4 if you are absolutely sure that you
1413 trust the BIOS to get all its memory reservations and usages
1414 right. If you know your BIOS have problems beyond the
1415 default 64K area, you can set this to 640 to avoid using the
1416 entire low memory range.
1417
1418 If you have doubts about the BIOS (e.g. suspend/resume does
1419 not work or there's kernel crashes after certain hardware
1420 hotplug events) then you might want to enable
1421 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1422 typical corruption patterns.
1423
1424 Leave this to the default value of 64 if you are unsure.
1425
1426 config MATH_EMULATION
1427 bool
1428 prompt "Math emulation" if X86_32
1429 ---help---
1430 Linux can emulate a math coprocessor (used for floating point
1431 operations) if you don't have one. 486DX and Pentium processors have
1432 a math coprocessor built in, 486SX and 386 do not, unless you added
1433 a 487DX or 387, respectively. (The messages during boot time can
1434 give you some hints here ["man dmesg"].) Everyone needs either a
1435 coprocessor or this emulation.
1436
1437 If you don't have a math coprocessor, you need to say Y here; if you
1438 say Y here even though you have a coprocessor, the coprocessor will
1439 be used nevertheless. (This behavior can be changed with the kernel
1440 command line option "no387", which comes handy if your coprocessor
1441 is broken. Try "man bootparam" or see the documentation of your boot
1442 loader (lilo or loadlin) about how to pass options to the kernel at
1443 boot time.) This means that it is a good idea to say Y here if you
1444 intend to use this kernel on different machines.
1445
1446 More information about the internals of the Linux math coprocessor
1447 emulation can be found in <file:arch/x86/math-emu/README>.
1448
1449 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1450 kernel, it won't hurt.
1451
1452 config MTRR
1453 def_bool y
1454 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1455 ---help---
1456 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1457 the Memory Type Range Registers (MTRRs) may be used to control
1458 processor access to memory ranges. This is most useful if you have
1459 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1460 allows bus write transfers to be combined into a larger transfer
1461 before bursting over the PCI/AGP bus. This can increase performance
1462 of image write operations 2.5 times or more. Saying Y here creates a
1463 /proc/mtrr file which may be used to manipulate your processor's
1464 MTRRs. Typically the X server should use this.
1465
1466 This code has a reasonably generic interface so that similar
1467 control registers on other processors can be easily supported
1468 as well:
1469
1470 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1471 Registers (ARRs) which provide a similar functionality to MTRRs. For
1472 these, the ARRs are used to emulate the MTRRs.
1473 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1474 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1475 write-combining. All of these processors are supported by this code
1476 and it makes sense to say Y here if you have one of them.
1477
1478 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1479 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1480 can lead to all sorts of problems, so it's good to say Y here.
1481
1482 You can safely say Y even if your machine doesn't have MTRRs, you'll
1483 just add about 9 KB to your kernel.
1484
1485 See <file:Documentation/x86/mtrr.txt> for more information.
1486
1487 config MTRR_SANITIZER
1488 def_bool y
1489 prompt "MTRR cleanup support"
1490 depends on MTRR
1491 ---help---
1492 Convert MTRR layout from continuous to discrete, so X drivers can
1493 add writeback entries.
1494
1495 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1496 The largest mtrr entry size for a continuous block can be set with
1497 mtrr_chunk_size.
1498
1499 If unsure, say Y.
1500
1501 config MTRR_SANITIZER_ENABLE_DEFAULT
1502 int "MTRR cleanup enable value (0-1)"
1503 range 0 1
1504 default "0"
1505 depends on MTRR_SANITIZER
1506 ---help---
1507 Enable mtrr cleanup default value
1508
1509 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1510 int "MTRR cleanup spare reg num (0-7)"
1511 range 0 7
1512 default "1"
1513 depends on MTRR_SANITIZER
1514 ---help---
1515 mtrr cleanup spare entries default, it can be changed via
1516 mtrr_spare_reg_nr=N on the kernel command line.
1517
1518 config X86_PAT
1519 def_bool y
1520 prompt "x86 PAT support" if EXPERT
1521 depends on MTRR
1522 ---help---
1523 Use PAT attributes to setup page level cache control.
1524
1525 PATs are the modern equivalents of MTRRs and are much more
1526 flexible than MTRRs.
1527
1528 Say N here if you see bootup problems (boot crash, boot hang,
1529 spontaneous reboots) or a non-working video driver.
1530
1531 If unsure, say Y.
1532
1533 config ARCH_USES_PG_UNCACHED
1534 def_bool y
1535 depends on X86_PAT
1536
1537 config ARCH_RANDOM
1538 def_bool y
1539 prompt "x86 architectural random number generator" if EXPERT
1540 ---help---
1541 Enable the x86 architectural RDRAND instruction
1542 (Intel Bull Mountain technology) to generate random numbers.
1543 If supported, this is a high bandwidth, cryptographically
1544 secure hardware random number generator.
1545
1546 config X86_SMAP
1547 def_bool y
1548 prompt "Supervisor Mode Access Prevention" if EXPERT
1549 ---help---
1550 Supervisor Mode Access Prevention (SMAP) is a security
1551 feature in newer Intel processors. There is a small
1552 performance cost if this enabled and turned on; there is
1553 also a small increase in the kernel size if this is enabled.
1554
1555 If unsure, say Y.
1556
1557 config EFI
1558 bool "EFI runtime service support"
1559 depends on ACPI
1560 select UCS2_STRING
1561 ---help---
1562 This enables the kernel to use EFI runtime services that are
1563 available (such as the EFI variable services).
1564
1565 This option is only useful on systems that have EFI firmware.
1566 In addition, you should use the latest ELILO loader available
1567 at <http://elilo.sourceforge.net> in order to take advantage
1568 of EFI runtime services. However, even with this option, the
1569 resultant kernel should continue to boot on existing non-EFI
1570 platforms.
1571
1572 config EFI_STUB
1573 bool "EFI stub support"
1574 depends on EFI
1575 ---help---
1576 This kernel feature allows a bzImage to be loaded directly
1577 by EFI firmware without the use of a bootloader.
1578
1579 See Documentation/x86/efi-stub.txt for more information.
1580
1581 config SECCOMP
1582 def_bool y
1583 prompt "Enable seccomp to safely compute untrusted bytecode"
1584 ---help---
1585 This kernel feature is useful for number crunching applications
1586 that may need to compute untrusted bytecode during their
1587 execution. By using pipes or other transports made available to
1588 the process as file descriptors supporting the read/write
1589 syscalls, it's possible to isolate those applications in
1590 their own address space using seccomp. Once seccomp is
1591 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1592 and the task is only allowed to execute a few safe syscalls
1593 defined by each seccomp mode.
1594
1595 If unsure, say Y. Only embedded should say N here.
1596
1597 config CC_STACKPROTECTOR
1598 bool "Enable -fstack-protector buffer overflow detection"
1599 ---help---
1600 This option turns on the -fstack-protector GCC feature. This
1601 feature puts, at the beginning of functions, a canary value on
1602 the stack just before the return address, and validates
1603 the value just before actually returning. Stack based buffer
1604 overflows (that need to overwrite this return address) now also
1605 overwrite the canary, which gets detected and the attack is then
1606 neutralized via a kernel panic.
1607
1608 This feature requires gcc version 4.2 or above, or a distribution
1609 gcc with the feature backported. Older versions are automatically
1610 detected and for those versions, this configuration option is
1611 ignored. (and a warning is printed during bootup)
1612
1613 source kernel/Kconfig.hz
1614
1615 config KEXEC
1616 bool "kexec system call"
1617 ---help---
1618 kexec is a system call that implements the ability to shutdown your
1619 current kernel, and to start another kernel. It is like a reboot
1620 but it is independent of the system firmware. And like a reboot
1621 you can start any kernel with it, not just Linux.
1622
1623 The name comes from the similarity to the exec system call.
1624
1625 It is an ongoing process to be certain the hardware in a machine
1626 is properly shutdown, so do not be surprised if this code does not
1627 initially work for you. It may help to enable device hotplugging
1628 support. As of this writing the exact hardware interface is
1629 strongly in flux, so no good recommendation can be made.
1630
1631 config CRASH_DUMP
1632 bool "kernel crash dumps"
1633 depends on X86_64 || (X86_32 && HIGHMEM)
1634 ---help---
1635 Generate crash dump after being started by kexec.
1636 This should be normally only set in special crash dump kernels
1637 which are loaded in the main kernel with kexec-tools into
1638 a specially reserved region and then later executed after
1639 a crash by kdump/kexec. The crash dump kernel must be compiled
1640 to a memory address not used by the main kernel or BIOS using
1641 PHYSICAL_START, or it must be built as a relocatable image
1642 (CONFIG_RELOCATABLE=y).
1643 For more details see Documentation/kdump/kdump.txt
1644
1645 config KEXEC_JUMP
1646 bool "kexec jump"
1647 depends on KEXEC && HIBERNATION
1648 ---help---
1649 Jump between original kernel and kexeced kernel and invoke
1650 code in physical address mode via KEXEC
1651
1652 config PHYSICAL_START
1653 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1654 default "0x1000000"
1655 ---help---
1656 This gives the physical address where the kernel is loaded.
1657
1658 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1659 bzImage will decompress itself to above physical address and
1660 run from there. Otherwise, bzImage will run from the address where
1661 it has been loaded by the boot loader and will ignore above physical
1662 address.
1663
1664 In normal kdump cases one does not have to set/change this option
1665 as now bzImage can be compiled as a completely relocatable image
1666 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1667 address. This option is mainly useful for the folks who don't want
1668 to use a bzImage for capturing the crash dump and want to use a
1669 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1670 to be specifically compiled to run from a specific memory area
1671 (normally a reserved region) and this option comes handy.
1672
1673 So if you are using bzImage for capturing the crash dump,
1674 leave the value here unchanged to 0x1000000 and set
1675 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1676 for capturing the crash dump change this value to start of
1677 the reserved region. In other words, it can be set based on
1678 the "X" value as specified in the "crashkernel=YM@XM"
1679 command line boot parameter passed to the panic-ed
1680 kernel. Please take a look at Documentation/kdump/kdump.txt
1681 for more details about crash dumps.
1682
1683 Usage of bzImage for capturing the crash dump is recommended as
1684 one does not have to build two kernels. Same kernel can be used
1685 as production kernel and capture kernel. Above option should have
1686 gone away after relocatable bzImage support is introduced. But it
1687 is present because there are users out there who continue to use
1688 vmlinux for dump capture. This option should go away down the
1689 line.
1690
1691 Don't change this unless you know what you are doing.
1692
1693 config RELOCATABLE
1694 bool "Build a relocatable kernel"
1695 default y
1696 ---help---
1697 This builds a kernel image that retains relocation information
1698 so it can be loaded someplace besides the default 1MB.
1699 The relocations tend to make the kernel binary about 10% larger,
1700 but are discarded at runtime.
1701
1702 One use is for the kexec on panic case where the recovery kernel
1703 must live at a different physical address than the primary
1704 kernel.
1705
1706 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1707 it has been loaded at and the compile time physical address
1708 (CONFIG_PHYSICAL_START) is ignored.
1709
1710 # Relocation on x86-32 needs some additional build support
1711 config X86_NEED_RELOCS
1712 def_bool y
1713 depends on X86_32 && RELOCATABLE
1714
1715 config PHYSICAL_ALIGN
1716 hex "Alignment value to which kernel should be aligned" if X86_32
1717 default "0x1000000"
1718 range 0x2000 0x1000000
1719 ---help---
1720 This value puts the alignment restrictions on physical address
1721 where kernel is loaded and run from. Kernel is compiled for an
1722 address which meets above alignment restriction.
1723
1724 If bootloader loads the kernel at a non-aligned address and
1725 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1726 address aligned to above value and run from there.
1727
1728 If bootloader loads the kernel at a non-aligned address and
1729 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1730 load address and decompress itself to the address it has been
1731 compiled for and run from there. The address for which kernel is
1732 compiled already meets above alignment restrictions. Hence the
1733 end result is that kernel runs from a physical address meeting
1734 above alignment restrictions.
1735
1736 Don't change this unless you know what you are doing.
1737
1738 config HOTPLUG_CPU
1739 bool "Support for hot-pluggable CPUs"
1740 depends on SMP
1741 ---help---
1742 Say Y here to allow turning CPUs off and on. CPUs can be
1743 controlled through /sys/devices/system/cpu.
1744 ( Note: power management support will enable this option
1745 automatically on SMP systems. )
1746 Say N if you want to disable CPU hotplug.
1747
1748 config BOOTPARAM_HOTPLUG_CPU0
1749 bool "Set default setting of cpu0_hotpluggable"
1750 default n
1751 depends on HOTPLUG_CPU
1752 ---help---
1753 Set whether default state of cpu0_hotpluggable is on or off.
1754
1755 Say Y here to enable CPU0 hotplug by default. If this switch
1756 is turned on, there is no need to give cpu0_hotplug kernel
1757 parameter and the CPU0 hotplug feature is enabled by default.
1758
1759 Please note: there are two known CPU0 dependencies if you want
1760 to enable the CPU0 hotplug feature either by this switch or by
1761 cpu0_hotplug kernel parameter.
1762
1763 First, resume from hibernate or suspend always starts from CPU0.
1764 So hibernate and suspend are prevented if CPU0 is offline.
1765
1766 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1767 offline if any interrupt can not migrate out of CPU0. There may
1768 be other CPU0 dependencies.
1769
1770 Please make sure the dependencies are under your control before
1771 you enable this feature.
1772
1773 Say N if you don't want to enable CPU0 hotplug feature by default.
1774 You still can enable the CPU0 hotplug feature at boot by kernel
1775 parameter cpu0_hotplug.
1776
1777 config DEBUG_HOTPLUG_CPU0
1778 def_bool n
1779 prompt "Debug CPU0 hotplug"
1780 depends on HOTPLUG_CPU
1781 ---help---
1782 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1783 soon as possible and boots up userspace with CPU0 offlined. User
1784 can online CPU0 back after boot time.
1785
1786 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1787 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1788 compilation or giving cpu0_hotplug kernel parameter at boot.
1789
1790 If unsure, say N.
1791
1792 config COMPAT_VDSO
1793 def_bool y
1794 prompt "Compat VDSO support"
1795 depends on X86_32 || IA32_EMULATION
1796 ---help---
1797 Map the 32-bit VDSO to the predictable old-style address too.
1798
1799 Say N here if you are running a sufficiently recent glibc
1800 version (2.3.3 or later), to remove the high-mapped
1801 VDSO mapping and to exclusively use the randomized VDSO.
1802
1803 If unsure, say Y.
1804
1805 config CMDLINE_BOOL
1806 bool "Built-in kernel command line"
1807 ---help---
1808 Allow for specifying boot arguments to the kernel at
1809 build time. On some systems (e.g. embedded ones), it is
1810 necessary or convenient to provide some or all of the
1811 kernel boot arguments with the kernel itself (that is,
1812 to not rely on the boot loader to provide them.)
1813
1814 To compile command line arguments into the kernel,
1815 set this option to 'Y', then fill in the
1816 the boot arguments in CONFIG_CMDLINE.
1817
1818 Systems with fully functional boot loaders (i.e. non-embedded)
1819 should leave this option set to 'N'.
1820
1821 config CMDLINE
1822 string "Built-in kernel command string"
1823 depends on CMDLINE_BOOL
1824 default ""
1825 ---help---
1826 Enter arguments here that should be compiled into the kernel
1827 image and used at boot time. If the boot loader provides a
1828 command line at boot time, it is appended to this string to
1829 form the full kernel command line, when the system boots.
1830
1831 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1832 change this behavior.
1833
1834 In most cases, the command line (whether built-in or provided
1835 by the boot loader) should specify the device for the root
1836 file system.
1837
1838 config CMDLINE_OVERRIDE
1839 bool "Built-in command line overrides boot loader arguments"
1840 depends on CMDLINE_BOOL
1841 ---help---
1842 Set this option to 'Y' to have the kernel ignore the boot loader
1843 command line, and use ONLY the built-in command line.
1844
1845 This is used to work around broken boot loaders. This should
1846 be set to 'N' under normal conditions.
1847
1848 endmenu
1849
1850 config ARCH_ENABLE_MEMORY_HOTPLUG
1851 def_bool y
1852 depends on X86_64 || (X86_32 && HIGHMEM)
1853
1854 config ARCH_ENABLE_MEMORY_HOTREMOVE
1855 def_bool y
1856 depends on MEMORY_HOTPLUG
1857
1858 config USE_PERCPU_NUMA_NODE_ID
1859 def_bool y
1860 depends on NUMA
1861
1862 menu "Power management and ACPI options"
1863
1864 config ARCH_HIBERNATION_HEADER
1865 def_bool y
1866 depends on X86_64 && HIBERNATION
1867
1868 source "kernel/power/Kconfig"
1869
1870 source "drivers/acpi/Kconfig"
1871
1872 source "drivers/sfi/Kconfig"
1873
1874 config X86_APM_BOOT
1875 def_bool y
1876 depends on APM
1877
1878 menuconfig APM
1879 tristate "APM (Advanced Power Management) BIOS support"
1880 depends on X86_32 && PM_SLEEP
1881 ---help---
1882 APM is a BIOS specification for saving power using several different
1883 techniques. This is mostly useful for battery powered laptops with
1884 APM compliant BIOSes. If you say Y here, the system time will be
1885 reset after a RESUME operation, the /proc/apm device will provide
1886 battery status information, and user-space programs will receive
1887 notification of APM "events" (e.g. battery status change).
1888
1889 If you select "Y" here, you can disable actual use of the APM
1890 BIOS by passing the "apm=off" option to the kernel at boot time.
1891
1892 Note that the APM support is almost completely disabled for
1893 machines with more than one CPU.
1894
1895 In order to use APM, you will need supporting software. For location
1896 and more information, read <file:Documentation/power/apm-acpi.txt>
1897 and the Battery Powered Linux mini-HOWTO, available from
1898 <http://www.tldp.org/docs.html#howto>.
1899
1900 This driver does not spin down disk drives (see the hdparm(8)
1901 manpage ("man 8 hdparm") for that), and it doesn't turn off
1902 VESA-compliant "green" monitors.
1903
1904 This driver does not support the TI 4000M TravelMate and the ACER
1905 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1906 desktop machines also don't have compliant BIOSes, and this driver
1907 may cause those machines to panic during the boot phase.
1908
1909 Generally, if you don't have a battery in your machine, there isn't
1910 much point in using this driver and you should say N. If you get
1911 random kernel OOPSes or reboots that don't seem to be related to
1912 anything, try disabling/enabling this option (or disabling/enabling
1913 APM in your BIOS).
1914
1915 Some other things you should try when experiencing seemingly random,
1916 "weird" problems:
1917
1918 1) make sure that you have enough swap space and that it is
1919 enabled.
1920 2) pass the "no-hlt" option to the kernel
1921 3) switch on floating point emulation in the kernel and pass
1922 the "no387" option to the kernel
1923 4) pass the "floppy=nodma" option to the kernel
1924 5) pass the "mem=4M" option to the kernel (thereby disabling
1925 all but the first 4 MB of RAM)
1926 6) make sure that the CPU is not over clocked.
1927 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1928 8) disable the cache from your BIOS settings
1929 9) install a fan for the video card or exchange video RAM
1930 10) install a better fan for the CPU
1931 11) exchange RAM chips
1932 12) exchange the motherboard.
1933
1934 To compile this driver as a module, choose M here: the
1935 module will be called apm.
1936
1937 if APM
1938
1939 config APM_IGNORE_USER_SUSPEND
1940 bool "Ignore USER SUSPEND"
1941 ---help---
1942 This option will ignore USER SUSPEND requests. On machines with a
1943 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1944 series notebooks, it is necessary to say Y because of a BIOS bug.
1945
1946 config APM_DO_ENABLE
1947 bool "Enable PM at boot time"
1948 ---help---
1949 Enable APM features at boot time. From page 36 of the APM BIOS
1950 specification: "When disabled, the APM BIOS does not automatically
1951 power manage devices, enter the Standby State, enter the Suspend
1952 State, or take power saving steps in response to CPU Idle calls."
1953 This driver will make CPU Idle calls when Linux is idle (unless this
1954 feature is turned off -- see "Do CPU IDLE calls", below). This
1955 should always save battery power, but more complicated APM features
1956 will be dependent on your BIOS implementation. You may need to turn
1957 this option off if your computer hangs at boot time when using APM
1958 support, or if it beeps continuously instead of suspending. Turn
1959 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1960 T400CDT. This is off by default since most machines do fine without
1961 this feature.
1962
1963 config APM_CPU_IDLE
1964 depends on CPU_IDLE
1965 bool "Make CPU Idle calls when idle"
1966 ---help---
1967 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1968 On some machines, this can activate improved power savings, such as
1969 a slowed CPU clock rate, when the machine is idle. These idle calls
1970 are made after the idle loop has run for some length of time (e.g.,
1971 333 mS). On some machines, this will cause a hang at boot time or
1972 whenever the CPU becomes idle. (On machines with more than one CPU,
1973 this option does nothing.)
1974
1975 config APM_DISPLAY_BLANK
1976 bool "Enable console blanking using APM"
1977 ---help---
1978 Enable console blanking using the APM. Some laptops can use this to
1979 turn off the LCD backlight when the screen blanker of the Linux
1980 virtual console blanks the screen. Note that this is only used by
1981 the virtual console screen blanker, and won't turn off the backlight
1982 when using the X Window system. This also doesn't have anything to
1983 do with your VESA-compliant power-saving monitor. Further, this
1984 option doesn't work for all laptops -- it might not turn off your
1985 backlight at all, or it might print a lot of errors to the console,
1986 especially if you are using gpm.
1987
1988 config APM_ALLOW_INTS
1989 bool "Allow interrupts during APM BIOS calls"
1990 ---help---
1991 Normally we disable external interrupts while we are making calls to
1992 the APM BIOS as a measure to lessen the effects of a badly behaving
1993 BIOS implementation. The BIOS should reenable interrupts if it
1994 needs to. Unfortunately, some BIOSes do not -- especially those in
1995 many of the newer IBM Thinkpads. If you experience hangs when you
1996 suspend, try setting this to Y. Otherwise, say N.
1997
1998 endif # APM
1999
2000 source "drivers/cpufreq/Kconfig"
2001
2002 source "drivers/cpuidle/Kconfig"
2003
2004 source "drivers/idle/Kconfig"
2005
2006 endmenu
2007
2008
2009 menu "Bus options (PCI etc.)"
2010
2011 config PCI
2012 bool "PCI support"
2013 default y
2014 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
2015 ---help---
2016 Find out whether you have a PCI motherboard. PCI is the name of a
2017 bus system, i.e. the way the CPU talks to the other stuff inside
2018 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2019 VESA. If you have PCI, say Y, otherwise N.
2020
2021 choice
2022 prompt "PCI access mode"
2023 depends on X86_32 && PCI
2024 default PCI_GOANY
2025 ---help---
2026 On PCI systems, the BIOS can be used to detect the PCI devices and
2027 determine their configuration. However, some old PCI motherboards
2028 have BIOS bugs and may crash if this is done. Also, some embedded
2029 PCI-based systems don't have any BIOS at all. Linux can also try to
2030 detect the PCI hardware directly without using the BIOS.
2031
2032 With this option, you can specify how Linux should detect the
2033 PCI devices. If you choose "BIOS", the BIOS will be used,
2034 if you choose "Direct", the BIOS won't be used, and if you
2035 choose "MMConfig", then PCI Express MMCONFIG will be used.
2036 If you choose "Any", the kernel will try MMCONFIG, then the
2037 direct access method and falls back to the BIOS if that doesn't
2038 work. If unsure, go with the default, which is "Any".
2039
2040 config PCI_GOBIOS
2041 bool "BIOS"
2042
2043 config PCI_GOMMCONFIG
2044 bool "MMConfig"
2045
2046 config PCI_GODIRECT
2047 bool "Direct"
2048
2049 config PCI_GOOLPC
2050 bool "OLPC XO-1"
2051 depends on OLPC
2052
2053 config PCI_GOANY
2054 bool "Any"
2055
2056 endchoice
2057
2058 config PCI_BIOS
2059 def_bool y
2060 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2061
2062 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2063 config PCI_DIRECT
2064 def_bool y
2065 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2066
2067 config PCI_MMCONFIG
2068 def_bool y
2069 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2070
2071 config PCI_OLPC
2072 def_bool y
2073 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2074
2075 config PCI_XEN
2076 def_bool y
2077 depends on PCI && XEN
2078 select SWIOTLB_XEN
2079
2080 config PCI_DOMAINS
2081 def_bool y
2082 depends on PCI
2083
2084 config PCI_MMCONFIG
2085 bool "Support mmconfig PCI config space access"
2086 depends on X86_64 && PCI && ACPI
2087
2088 config PCI_CNB20LE_QUIRK
2089 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2090 depends on PCI
2091 help
2092 Read the PCI windows out of the CNB20LE host bridge. This allows
2093 PCI hotplug to work on systems with the CNB20LE chipset which do
2094 not have ACPI.
2095
2096 There's no public spec for this chipset, and this functionality
2097 is known to be incomplete.
2098
2099 You should say N unless you know you need this.
2100
2101 source "drivers/pci/pcie/Kconfig"
2102
2103 source "drivers/pci/Kconfig"
2104
2105 # x86_64 have no ISA slots, but can have ISA-style DMA.
2106 config ISA_DMA_API
2107 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2108 default y
2109 help
2110 Enables ISA-style DMA support for devices requiring such controllers.
2111 If unsure, say Y.
2112
2113 if X86_32
2114
2115 config ISA
2116 bool "ISA support"
2117 ---help---
2118 Find out whether you have ISA slots on your motherboard. ISA is the
2119 name of a bus system, i.e. the way the CPU talks to the other stuff
2120 inside your box. Other bus systems are PCI, EISA, MicroChannel
2121 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2122 newer boards don't support it. If you have ISA, say Y, otherwise N.
2123
2124 config EISA
2125 bool "EISA support"
2126 depends on ISA
2127 ---help---
2128 The Extended Industry Standard Architecture (EISA) bus was
2129 developed as an open alternative to the IBM MicroChannel bus.
2130
2131 The EISA bus provided some of the features of the IBM MicroChannel
2132 bus while maintaining backward compatibility with cards made for
2133 the older ISA bus. The EISA bus saw limited use between 1988 and
2134 1995 when it was made obsolete by the PCI bus.
2135
2136 Say Y here if you are building a kernel for an EISA-based machine.
2137
2138 Otherwise, say N.
2139
2140 source "drivers/eisa/Kconfig"
2141
2142 config SCx200
2143 tristate "NatSemi SCx200 support"
2144 ---help---
2145 This provides basic support for National Semiconductor's
2146 (now AMD's) Geode processors. The driver probes for the
2147 PCI-IDs of several on-chip devices, so its a good dependency
2148 for other scx200_* drivers.
2149
2150 If compiled as a module, the driver is named scx200.
2151
2152 config SCx200HR_TIMER
2153 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2154 depends on SCx200
2155 default y
2156 ---help---
2157 This driver provides a clocksource built upon the on-chip
2158 27MHz high-resolution timer. Its also a workaround for
2159 NSC Geode SC-1100's buggy TSC, which loses time when the
2160 processor goes idle (as is done by the scheduler). The
2161 other workaround is idle=poll boot option.
2162
2163 config OLPC
2164 bool "One Laptop Per Child support"
2165 depends on !X86_PAE
2166 select GPIOLIB
2167 select OF
2168 select OF_PROMTREE
2169 select IRQ_DOMAIN
2170 ---help---
2171 Add support for detecting the unique features of the OLPC
2172 XO hardware.
2173
2174 config OLPC_XO1_PM
2175 bool "OLPC XO-1 Power Management"
2176 depends on OLPC && MFD_CS5535 && PM_SLEEP
2177 select MFD_CORE
2178 ---help---
2179 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2180
2181 config OLPC_XO1_RTC
2182 bool "OLPC XO-1 Real Time Clock"
2183 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2184 ---help---
2185 Add support for the XO-1 real time clock, which can be used as a
2186 programmable wakeup source.
2187
2188 config OLPC_XO1_SCI
2189 bool "OLPC XO-1 SCI extras"
2190 depends on OLPC && OLPC_XO1_PM
2191 depends on INPUT=y
2192 select POWER_SUPPLY
2193 select GPIO_CS5535
2194 select MFD_CORE
2195 ---help---
2196 Add support for SCI-based features of the OLPC XO-1 laptop:
2197 - EC-driven system wakeups
2198 - Power button
2199 - Ebook switch
2200 - Lid switch
2201 - AC adapter status updates
2202 - Battery status updates
2203
2204 config OLPC_XO15_SCI
2205 bool "OLPC XO-1.5 SCI extras"
2206 depends on OLPC && ACPI
2207 select POWER_SUPPLY
2208 ---help---
2209 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2210 - EC-driven system wakeups
2211 - AC adapter status updates
2212 - Battery status updates
2213
2214 config ALIX
2215 bool "PCEngines ALIX System Support (LED setup)"
2216 select GPIOLIB
2217 ---help---
2218 This option enables system support for the PCEngines ALIX.
2219 At present this just sets up LEDs for GPIO control on
2220 ALIX2/3/6 boards. However, other system specific setup should
2221 get added here.
2222
2223 Note: You must still enable the drivers for GPIO and LED support
2224 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2225
2226 Note: You have to set alix.force=1 for boards with Award BIOS.
2227
2228 config NET5501
2229 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2230 select GPIOLIB
2231 ---help---
2232 This option enables system support for the Soekris Engineering net5501.
2233
2234 config GEOS
2235 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2236 select GPIOLIB
2237 depends on DMI
2238 ---help---
2239 This option enables system support for the Traverse Technologies GEOS.
2240
2241 config TS5500
2242 bool "Technologic Systems TS-5500 platform support"
2243 depends on MELAN
2244 select CHECK_SIGNATURE
2245 select NEW_LEDS
2246 select LEDS_CLASS
2247 ---help---
2248 This option enables system support for the Technologic Systems TS-5500.
2249
2250 endif # X86_32
2251
2252 config AMD_NB
2253 def_bool y
2254 depends on CPU_SUP_AMD && PCI
2255
2256 source "drivers/pcmcia/Kconfig"
2257
2258 source "drivers/pci/hotplug/Kconfig"
2259
2260 config RAPIDIO
2261 bool "RapidIO support"
2262 depends on PCI
2263 default n
2264 help
2265 If you say Y here, the kernel will include drivers and
2266 infrastructure code to support RapidIO interconnect devices.
2267
2268 source "drivers/rapidio/Kconfig"
2269
2270 endmenu
2271
2272
2273 menu "Executable file formats / Emulations"
2274
2275 source "fs/Kconfig.binfmt"
2276
2277 config IA32_EMULATION
2278 bool "IA32 Emulation"
2279 depends on X86_64
2280 select BINFMT_ELF
2281 select COMPAT_BINFMT_ELF
2282 select HAVE_UID16
2283 ---help---
2284 Include code to run legacy 32-bit programs under a
2285 64-bit kernel. You should likely turn this on, unless you're
2286 100% sure that you don't have any 32-bit programs left.
2287
2288 config IA32_AOUT
2289 tristate "IA32 a.out support"
2290 depends on IA32_EMULATION
2291 ---help---
2292 Support old a.out binaries in the 32bit emulation.
2293
2294 config X86_X32
2295 bool "x32 ABI for 64-bit mode"
2296 depends on X86_64 && IA32_EMULATION
2297 ---help---
2298 Include code to run binaries for the x32 native 32-bit ABI
2299 for 64-bit processors. An x32 process gets access to the
2300 full 64-bit register file and wide data path while leaving
2301 pointers at 32 bits for smaller memory footprint.
2302
2303 You will need a recent binutils (2.22 or later) with
2304 elf32_x86_64 support enabled to compile a kernel with this
2305 option set.
2306
2307 config COMPAT
2308 def_bool y
2309 depends on IA32_EMULATION || X86_X32
2310 select ARCH_WANT_OLD_COMPAT_IPC
2311
2312 if COMPAT
2313 config COMPAT_FOR_U64_ALIGNMENT
2314 def_bool y
2315
2316 config SYSVIPC_COMPAT
2317 def_bool y
2318 depends on SYSVIPC
2319
2320 config KEYS_COMPAT
2321 def_bool y
2322 depends on KEYS
2323 endif
2324
2325 endmenu
2326
2327
2328 config HAVE_ATOMIC_IOMAP
2329 def_bool y
2330 depends on X86_32
2331
2332 config HAVE_TEXT_POKE_SMP
2333 bool
2334 select STOP_MACHINE if SMP
2335
2336 config X86_DEV_DMA_OPS
2337 bool
2338 depends on X86_64 || STA2X11
2339
2340 config X86_DMA_REMAP
2341 bool
2342 depends on STA2X11
2343
2344 source "net/Kconfig"
2345
2346 source "drivers/Kconfig"
2347
2348 source "drivers/firmware/Kconfig"
2349
2350 source "fs/Kconfig"
2351
2352 source "arch/x86/Kconfig.debug"
2353
2354 source "security/Kconfig"
2355
2356 source "crypto/Kconfig"
2357
2358 source "arch/x86/kvm/Kconfig"
2359
2360 source "lib/Kconfig"
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