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