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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 select ARCH_USE_CMPXCHG_LOCKREF
20
21 ### Arch settings
22 config X86
23 def_bool y
24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
25 select ARCH_MIGHT_HAVE_PC_PARPORT
26 select HAVE_AOUT if X86_32
27 select HAVE_UNSTABLE_SCHED_CLOCK
28 select ARCH_SUPPORTS_NUMA_BALANCING
29 select ARCH_SUPPORTS_INT128 if X86_64
30 select ARCH_WANTS_PROT_NUMA_PROT_NONE
31 select HAVE_IDE
32 select HAVE_OPROFILE
33 select HAVE_PCSPKR_PLATFORM
34 select HAVE_PERF_EVENTS
35 select HAVE_IOREMAP_PROT
36 select HAVE_KPROBES
37 select HAVE_MEMBLOCK
38 select HAVE_MEMBLOCK_NODE_MAP
39 select ARCH_DISCARD_MEMBLOCK
40 select ARCH_WANT_OPTIONAL_GPIOLIB
41 select ARCH_WANT_FRAME_POINTERS
42 select HAVE_DMA_ATTRS
43 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
44 select HAVE_KRETPROBES
45 select HAVE_OPTPROBES
46 select HAVE_KPROBES_ON_FTRACE
47 select HAVE_FTRACE_MCOUNT_RECORD
48 select HAVE_FENTRY if X86_64
49 select HAVE_C_RECORDMCOUNT
50 select HAVE_DYNAMIC_FTRACE
51 select HAVE_DYNAMIC_FTRACE_WITH_REGS
52 select HAVE_FUNCTION_TRACER
53 select HAVE_FUNCTION_GRAPH_TRACER
54 select HAVE_FUNCTION_GRAPH_FP_TEST
55 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
56 select HAVE_SYSCALL_TRACEPOINTS
57 select SYSCTL_EXCEPTION_TRACE
58 select HAVE_KVM
59 select HAVE_ARCH_KGDB
60 select HAVE_ARCH_TRACEHOOK
61 select HAVE_GENERIC_DMA_COHERENT if X86_32
62 select HAVE_EFFICIENT_UNALIGNED_ACCESS
63 select USER_STACKTRACE_SUPPORT
64 select HAVE_REGS_AND_STACK_ACCESS_API
65 select HAVE_DMA_API_DEBUG
66 select HAVE_KERNEL_GZIP
67 select HAVE_KERNEL_BZIP2
68 select HAVE_KERNEL_LZMA
69 select HAVE_KERNEL_XZ
70 select HAVE_KERNEL_LZO
71 select HAVE_KERNEL_LZ4
72 select HAVE_HW_BREAKPOINT
73 select HAVE_MIXED_BREAKPOINTS_REGS
74 select PERF_EVENTS
75 select HAVE_PERF_EVENTS_NMI
76 select HAVE_PERF_REGS
77 select HAVE_PERF_USER_STACK_DUMP
78 select HAVE_DEBUG_KMEMLEAK
79 select ANON_INODES
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_CMPXCHG_LOCAL
82 select HAVE_CMPXCHG_DOUBLE
83 select HAVE_ARCH_KMEMCHECK
84 select HAVE_USER_RETURN_NOTIFIER
85 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
86 select HAVE_ARCH_JUMP_LABEL
87 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
88 select SPARSE_IRQ
89 select GENERIC_FIND_FIRST_BIT
90 select GENERIC_IRQ_PROBE
91 select GENERIC_PENDING_IRQ if SMP
92 select GENERIC_IRQ_SHOW
93 select GENERIC_CLOCKEVENTS_MIN_ADJUST
94 select IRQ_FORCED_THREADING
95 select HAVE_BPF_JIT if X86_64
96 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
97 select CLKEVT_I8253
98 select ARCH_HAVE_NMI_SAFE_CMPXCHG
99 select GENERIC_IOMAP
100 select DCACHE_WORD_ACCESS
101 select GENERIC_SMP_IDLE_THREAD
102 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
103 select HAVE_ARCH_SECCOMP_FILTER
104 select BUILDTIME_EXTABLE_SORT
105 select GENERIC_CMOS_UPDATE
106 select HAVE_ARCH_SOFT_DIRTY
107 select CLOCKSOURCE_WATCHDOG
108 select GENERIC_CLOCKEVENTS
109 select ARCH_CLOCKSOURCE_DATA if X86_64
110 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
111 select GENERIC_TIME_VSYSCALL if X86_64
112 select KTIME_SCALAR if X86_32
113 select GENERIC_STRNCPY_FROM_USER
114 select GENERIC_STRNLEN_USER
115 select HAVE_CONTEXT_TRACKING if X86_64
116 select HAVE_IRQ_TIME_ACCOUNTING
117 select VIRT_TO_BUS
118 select MODULES_USE_ELF_REL if X86_32
119 select MODULES_USE_ELF_RELA if X86_64
120 select CLONE_BACKWARDS if X86_32
121 select ARCH_USE_BUILTIN_BSWAP
122 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
123 select OLD_SIGACTION if X86_32
124 select COMPAT_OLD_SIGACTION if IA32_EMULATION
125 select RTC_LIB
126 select HAVE_DEBUG_STACKOVERFLOW
127 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
128 select HAVE_CC_STACKPROTECTOR
129
130 config INSTRUCTION_DECODER
131 def_bool y
132 depends on KPROBES || PERF_EVENTS || UPROBES
133
134 config OUTPUT_FORMAT
135 string
136 default "elf32-i386" if X86_32
137 default "elf64-x86-64" if X86_64
138
139 config ARCH_DEFCONFIG
140 string
141 default "arch/x86/configs/i386_defconfig" if X86_32
142 default "arch/x86/configs/x86_64_defconfig" if X86_64
143
144 config LOCKDEP_SUPPORT
145 def_bool y
146
147 config STACKTRACE_SUPPORT
148 def_bool y
149
150 config HAVE_LATENCYTOP_SUPPORT
151 def_bool y
152
153 config MMU
154 def_bool y
155
156 config SBUS
157 bool
158
159 config NEED_DMA_MAP_STATE
160 def_bool y
161 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
162
163 config NEED_SG_DMA_LENGTH
164 def_bool y
165
166 config GENERIC_ISA_DMA
167 def_bool y
168 depends on ISA_DMA_API
169
170 config GENERIC_BUG
171 def_bool y
172 depends on BUG
173 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
174
175 config GENERIC_BUG_RELATIVE_POINTERS
176 bool
177
178 config GENERIC_HWEIGHT
179 def_bool y
180
181 config ARCH_MAY_HAVE_PC_FDC
182 def_bool y
183 depends on ISA_DMA_API
184
185 config RWSEM_XCHGADD_ALGORITHM
186 def_bool y
187
188 config GENERIC_CALIBRATE_DELAY
189 def_bool y
190
191 config ARCH_HAS_CPU_RELAX
192 def_bool y
193
194 config ARCH_HAS_CACHE_LINE_SIZE
195 def_bool y
196
197 config ARCH_HAS_CPU_AUTOPROBE
198 def_bool y
199
200 config HAVE_SETUP_PER_CPU_AREA
201 def_bool y
202
203 config NEED_PER_CPU_EMBED_FIRST_CHUNK
204 def_bool y
205
206 config NEED_PER_CPU_PAGE_FIRST_CHUNK
207 def_bool y
208
209 config ARCH_HIBERNATION_POSSIBLE
210 def_bool y
211
212 config ARCH_SUSPEND_POSSIBLE
213 def_bool y
214
215 config ARCH_WANT_HUGE_PMD_SHARE
216 def_bool y
217
218 config ARCH_WANT_GENERAL_HUGETLB
219 def_bool y
220
221 config ZONE_DMA32
222 bool
223 default X86_64
224
225 config AUDIT_ARCH
226 bool
227 default X86_64
228
229 config ARCH_SUPPORTS_OPTIMIZED_INLINING
230 def_bool y
231
232 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
233 def_bool y
234
235 config HAVE_INTEL_TXT
236 def_bool y
237 depends on INTEL_IOMMU && ACPI
238
239 config X86_32_SMP
240 def_bool y
241 depends on X86_32 && SMP
242
243 config X86_64_SMP
244 def_bool y
245 depends on X86_64 && SMP
246
247 config X86_HT
248 def_bool y
249 depends on SMP
250
251 config X86_32_LAZY_GS
252 def_bool y
253 depends on X86_32 && !CC_STACKPROTECTOR
254
255 config ARCH_HWEIGHT_CFLAGS
256 string
257 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
258 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
259
260 config ARCH_SUPPORTS_UPROBES
261 def_bool y
262
263 source "init/Kconfig"
264 source "kernel/Kconfig.freezer"
265
266 menu "Processor type and features"
267
268 config ZONE_DMA
269 bool "DMA memory allocation support" if EXPERT
270 default y
271 help
272 DMA memory allocation support allows devices with less than 32-bit
273 addressing to allocate within the first 16MB of address space.
274 Disable if no such devices will be used.
275
276 If unsure, say Y.
277
278 config SMP
279 bool "Symmetric multi-processing support"
280 ---help---
281 This enables support for systems with more than one CPU. If you have
282 a system with only one CPU, like most personal computers, say N. If
283 you have a system with more than one CPU, say Y.
284
285 If you say N here, the kernel will run on single and multiprocessor
286 machines, but will use only one CPU of a multiprocessor machine. If
287 you say Y here, the kernel will run on many, but not all,
288 singleprocessor machines. On a singleprocessor machine, the kernel
289 will run faster if you say N here.
290
291 Note that if you say Y here and choose architecture "586" or
292 "Pentium" under "Processor family", the kernel will not work on 486
293 architectures. Similarly, multiprocessor kernels for the "PPro"
294 architecture may not work on all Pentium based boards.
295
296 People using multiprocessor machines who say Y here should also say
297 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
298 Management" code will be disabled if you say Y here.
299
300 See also <file:Documentation/x86/i386/IO-APIC.txt>,
301 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
302 <http://www.tldp.org/docs.html#howto>.
303
304 If you don't know what to do here, say N.
305
306 config X86_X2APIC
307 bool "Support x2apic"
308 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
309 ---help---
310 This enables x2apic support on CPUs that have this feature.
311
312 This allows 32-bit apic IDs (so it can support very large systems),
313 and accesses the local apic via MSRs not via mmio.
314
315 If you don't know what to do here, say N.
316
317 config X86_MPPARSE
318 bool "Enable MPS table" if ACPI || SFI
319 default y
320 depends on X86_LOCAL_APIC
321 ---help---
322 For old smp systems that do not have proper acpi support. Newer systems
323 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
324
325 config X86_BIGSMP
326 bool "Support for big SMP systems with more than 8 CPUs"
327 depends on X86_32 && SMP
328 ---help---
329 This option is needed for the systems that have more than 8 CPUs
330
331 config GOLDFISH
332 def_bool y
333 depends on X86_GOLDFISH
334
335 if X86_32
336 config X86_EXTENDED_PLATFORM
337 bool "Support for extended (non-PC) x86 platforms"
338 default y
339 ---help---
340 If you disable this option then the kernel will only support
341 standard PC platforms. (which covers the vast majority of
342 systems out there.)
343
344 If you enable this option then you'll be able to select support
345 for the following (non-PC) 32 bit x86 platforms:
346 Goldfish (Android emulator)
347 AMD Elan
348 NUMAQ (IBM/Sequent)
349 RDC R-321x SoC
350 SGI 320/540 (Visual Workstation)
351 STA2X11-based (e.g. Northville)
352 Summit/EXA (IBM x440)
353 Unisys ES7000 IA32 series
354 Moorestown MID devices
355
356 If you have one of these systems, or if you want to build a
357 generic distribution kernel, say Y here - otherwise say N.
358 endif
359
360 if X86_64
361 config X86_EXTENDED_PLATFORM
362 bool "Support for extended (non-PC) x86 platforms"
363 default y
364 ---help---
365 If you disable this option then the kernel will only support
366 standard PC platforms. (which covers the vast majority of
367 systems out there.)
368
369 If you enable this option then you'll be able to select support
370 for the following (non-PC) 64 bit x86 platforms:
371 Numascale NumaChip
372 ScaleMP vSMP
373 SGI Ultraviolet
374
375 If you have one of these systems, or if you want to build a
376 generic distribution kernel, say Y here - otherwise say N.
377 endif
378 # This is an alphabetically sorted list of 64 bit extended platforms
379 # Please maintain the alphabetic order if and when there are additions
380 config X86_NUMACHIP
381 bool "Numascale NumaChip"
382 depends on X86_64
383 depends on X86_EXTENDED_PLATFORM
384 depends on NUMA
385 depends on SMP
386 depends on X86_X2APIC
387 depends on PCI_MMCONFIG
388 ---help---
389 Adds support for Numascale NumaChip large-SMP systems. Needed to
390 enable more than ~168 cores.
391 If you don't have one of these, you should say N here.
392
393 config X86_VSMP
394 bool "ScaleMP vSMP"
395 select HYPERVISOR_GUEST
396 select PARAVIRT
397 depends on X86_64 && PCI
398 depends on X86_EXTENDED_PLATFORM
399 depends on SMP
400 ---help---
401 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
402 supposed to run on these EM64T-based machines. Only choose this option
403 if you have one of these machines.
404
405 config X86_UV
406 bool "SGI Ultraviolet"
407 depends on X86_64
408 depends on X86_EXTENDED_PLATFORM
409 depends on NUMA
410 depends on X86_X2APIC
411 ---help---
412 This option is needed in order to support SGI Ultraviolet systems.
413 If you don't have one of these, you should say N here.
414
415 # Following is an alphabetically sorted list of 32 bit extended platforms
416 # Please maintain the alphabetic order if and when there are additions
417
418 config X86_GOLDFISH
419 bool "Goldfish (Virtual Platform)"
420 depends on X86_32
421 depends on X86_EXTENDED_PLATFORM
422 ---help---
423 Enable support for the Goldfish virtual platform used primarily
424 for Android development. Unless you are building for the Android
425 Goldfish emulator say N here.
426
427 config X86_INTEL_CE
428 bool "CE4100 TV platform"
429 depends on PCI
430 depends on PCI_GODIRECT
431 depends on X86_32
432 depends on X86_EXTENDED_PLATFORM
433 select X86_REBOOTFIXUPS
434 select OF
435 select OF_EARLY_FLATTREE
436 select IRQ_DOMAIN
437 ---help---
438 Select for the Intel CE media processor (CE4100) SOC.
439 This option compiles in support for the CE4100 SOC for settop
440 boxes and media devices.
441
442 config X86_WANT_INTEL_MID
443 bool "Intel MID platform support"
444 depends on X86_32
445 depends on X86_EXTENDED_PLATFORM
446 ---help---
447 Select to build a kernel capable of supporting Intel MID platform
448 systems which do not have the PCI legacy interfaces (Moorestown,
449 Medfield). If you are building for a PC class system say N here.
450
451 if X86_WANT_INTEL_MID
452
453 config X86_INTEL_MID
454 bool
455
456 config X86_MDFLD
457 bool "Medfield MID platform"
458 depends on PCI
459 depends on PCI_GOANY
460 depends on X86_IO_APIC
461 select X86_INTEL_MID
462 select SFI
463 select DW_APB_TIMER
464 select APB_TIMER
465 select I2C
466 select SPI
467 select INTEL_SCU_IPC
468 select X86_PLATFORM_DEVICES
469 select MFD_INTEL_MSIC
470 ---help---
471 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
472 Internet Device(MID) platform.
473 Unlike standard x86 PCs, Medfield does not have many legacy devices
474 nor standard legacy replacement devices/features. e.g. Medfield does
475 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
476
477 endif
478
479 config X86_INTEL_LPSS
480 bool "Intel Low Power Subsystem Support"
481 depends on ACPI
482 select COMMON_CLK
483 select PINCTRL
484 ---help---
485 Select to build support for Intel Low Power Subsystem such as
486 found on Intel Lynxpoint PCH. Selecting this option enables
487 things like clock tree (common clock framework) and pincontrol
488 which are needed by the LPSS peripheral drivers.
489
490 config X86_RDC321X
491 bool "RDC R-321x SoC"
492 depends on X86_32
493 depends on X86_EXTENDED_PLATFORM
494 select M486
495 select X86_REBOOTFIXUPS
496 ---help---
497 This option is needed for RDC R-321x system-on-chip, also known
498 as R-8610-(G).
499 If you don't have one of these chips, you should say N here.
500
501 config X86_32_NON_STANDARD
502 bool "Support non-standard 32-bit SMP architectures"
503 depends on X86_32 && SMP
504 depends on X86_EXTENDED_PLATFORM
505 ---help---
506 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
507 STA2X11, default subarchitectures. It is intended for a generic
508 binary kernel. If you select them all, kernel will probe it
509 one by one and will fallback to default.
510
511 # Alphabetically sorted list of Non standard 32 bit platforms
512
513 config X86_NUMAQ
514 bool "NUMAQ (IBM/Sequent)"
515 depends on X86_32_NON_STANDARD
516 depends on PCI
517 select NUMA
518 select X86_MPPARSE
519 ---help---
520 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
521 NUMA multiquad box. This changes the way that processors are
522 bootstrapped, and uses Clustered Logical APIC addressing mode instead
523 of Flat Logical. You will need a new lynxer.elf file to flash your
524 firmware with - send email to <Martin.Bligh@us.ibm.com>.
525
526 config X86_SUPPORTS_MEMORY_FAILURE
527 def_bool y
528 # MCE code calls memory_failure():
529 depends on X86_MCE
530 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
531 depends on !X86_NUMAQ
532 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
533 depends on X86_64 || !SPARSEMEM
534 select ARCH_SUPPORTS_MEMORY_FAILURE
535
536 config X86_VISWS
537 bool "SGI 320/540 (Visual Workstation)"
538 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
539 depends on X86_32_NON_STANDARD
540 ---help---
541 The SGI Visual Workstation series is an IA32-based workstation
542 based on SGI systems chips with some legacy PC hardware attached.
543
544 Say Y here to create a kernel to run on the SGI 320 or 540.
545
546 A kernel compiled for the Visual Workstation will run on general
547 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
548
549 config STA2X11
550 bool "STA2X11 Companion Chip Support"
551 depends on X86_32_NON_STANDARD && PCI
552 select X86_DEV_DMA_OPS
553 select X86_DMA_REMAP
554 select SWIOTLB
555 select MFD_STA2X11
556 select ARCH_REQUIRE_GPIOLIB
557 default n
558 ---help---
559 This adds support for boards based on the STA2X11 IO-Hub,
560 a.k.a. "ConneXt". The chip is used in place of the standard
561 PC chipset, so all "standard" peripherals are missing. If this
562 option is selected the kernel will still be able to boot on
563 standard PC machines.
564
565 config X86_SUMMIT
566 bool "Summit/EXA (IBM x440)"
567 depends on X86_32_NON_STANDARD
568 ---help---
569 This option is needed for IBM systems that use the Summit/EXA chipset.
570 In particular, it is needed for the x440.
571
572 config X86_ES7000
573 bool "Unisys ES7000 IA32 series"
574 depends on X86_32_NON_STANDARD && X86_BIGSMP
575 ---help---
576 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
577 supposed to run on an IA32-based Unisys ES7000 system.
578
579 config X86_32_IRIS
580 tristate "Eurobraille/Iris poweroff module"
581 depends on X86_32
582 ---help---
583 The Iris machines from EuroBraille do not have APM or ACPI support
584 to shut themselves down properly. A special I/O sequence is
585 needed to do so, which is what this module does at
586 kernel shutdown.
587
588 This is only for Iris machines from EuroBraille.
589
590 If unused, say N.
591
592 config SCHED_OMIT_FRAME_POINTER
593 def_bool y
594 prompt "Single-depth WCHAN output"
595 depends on X86
596 ---help---
597 Calculate simpler /proc/<PID>/wchan values. If this option
598 is disabled then wchan values will recurse back to the
599 caller function. This provides more accurate wchan values,
600 at the expense of slightly more scheduling overhead.
601
602 If in doubt, say "Y".
603
604 menuconfig HYPERVISOR_GUEST
605 bool "Linux guest support"
606 ---help---
607 Say Y here to enable options for running Linux under various hyper-
608 visors. This option enables basic hypervisor detection and platform
609 setup.
610
611 If you say N, all options in this submenu will be skipped and
612 disabled, and Linux guest support won't be built in.
613
614 if HYPERVISOR_GUEST
615
616 config PARAVIRT
617 bool "Enable paravirtualization code"
618 ---help---
619 This changes the kernel so it can modify itself when it is run
620 under a hypervisor, potentially improving performance significantly
621 over full virtualization. However, when run without a hypervisor
622 the kernel is theoretically slower and slightly larger.
623
624 config PARAVIRT_DEBUG
625 bool "paravirt-ops debugging"
626 depends on PARAVIRT && DEBUG_KERNEL
627 ---help---
628 Enable to debug paravirt_ops internals. Specifically, BUG if
629 a paravirt_op is missing when it is called.
630
631 config PARAVIRT_SPINLOCKS
632 bool "Paravirtualization layer for spinlocks"
633 depends on PARAVIRT && SMP
634 select UNINLINE_SPIN_UNLOCK
635 ---help---
636 Paravirtualized spinlocks allow a pvops backend to replace the
637 spinlock implementation with something virtualization-friendly
638 (for example, block the virtual CPU rather than spinning).
639
640 It has a minimal impact on native kernels and gives a nice performance
641 benefit on paravirtualized KVM / Xen kernels.
642
643 If you are unsure how to answer this question, answer Y.
644
645 source "arch/x86/xen/Kconfig"
646
647 config KVM_GUEST
648 bool "KVM Guest support (including kvmclock)"
649 depends on PARAVIRT
650 select PARAVIRT_CLOCK
651 default y
652 ---help---
653 This option enables various optimizations for running under the KVM
654 hypervisor. It includes a paravirtualized clock, so that instead
655 of relying on a PIT (or probably other) emulation by the
656 underlying device model, the host provides the guest with
657 timing infrastructure such as time of day, and system time
658
659 config KVM_DEBUG_FS
660 bool "Enable debug information for KVM Guests in debugfs"
661 depends on KVM_GUEST && DEBUG_FS
662 default n
663 ---help---
664 This option enables collection of various statistics for KVM guest.
665 Statistics are displayed in debugfs filesystem. Enabling this option
666 may incur significant overhead.
667
668 source "arch/x86/lguest/Kconfig"
669
670 config PARAVIRT_TIME_ACCOUNTING
671 bool "Paravirtual steal time accounting"
672 depends on PARAVIRT
673 default n
674 ---help---
675 Select this option to enable fine granularity task steal time
676 accounting. Time spent executing other tasks in parallel with
677 the current vCPU is discounted from the vCPU power. To account for
678 that, there can be a small performance impact.
679
680 If in doubt, say N here.
681
682 config PARAVIRT_CLOCK
683 bool
684
685 endif #HYPERVISOR_GUEST
686
687 config NO_BOOTMEM
688 def_bool y
689
690 config MEMTEST
691 bool "Memtest"
692 ---help---
693 This option adds a kernel parameter 'memtest', which allows memtest
694 to be set.
695 memtest=0, mean disabled; -- default
696 memtest=1, mean do 1 test pattern;
697 ...
698 memtest=4, mean do 4 test patterns.
699 If you are unsure how to answer this question, answer N.
700
701 config X86_SUMMIT_NUMA
702 def_bool y
703 depends on X86_32 && NUMA && X86_32_NON_STANDARD
704
705 config X86_CYCLONE_TIMER
706 def_bool y
707 depends on X86_SUMMIT
708
709 source "arch/x86/Kconfig.cpu"
710
711 config HPET_TIMER
712 def_bool X86_64
713 prompt "HPET Timer Support" if X86_32
714 ---help---
715 Use the IA-PC HPET (High Precision Event Timer) to manage
716 time in preference to the PIT and RTC, if a HPET is
717 present.
718 HPET is the next generation timer replacing legacy 8254s.
719 The HPET provides a stable time base on SMP
720 systems, unlike the TSC, but it is more expensive to access,
721 as it is off-chip. You can find the HPET spec at
722 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
723
724 You can safely choose Y here. However, HPET will only be
725 activated if the platform and the BIOS support this feature.
726 Otherwise the 8254 will be used for timing services.
727
728 Choose N to continue using the legacy 8254 timer.
729
730 config HPET_EMULATE_RTC
731 def_bool y
732 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
733
734 config APB_TIMER
735 def_bool y if X86_INTEL_MID
736 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
737 select DW_APB_TIMER
738 depends on X86_INTEL_MID && SFI
739 help
740 APB timer is the replacement for 8254, HPET on X86 MID platforms.
741 The APBT provides a stable time base on SMP
742 systems, unlike the TSC, but it is more expensive to access,
743 as it is off-chip. APB timers are always running regardless of CPU
744 C states, they are used as per CPU clockevent device when possible.
745
746 # Mark as expert because too many people got it wrong.
747 # The code disables itself when not needed.
748 config DMI
749 default y
750 bool "Enable DMI scanning" if EXPERT
751 ---help---
752 Enabled scanning of DMI to identify machine quirks. Say Y
753 here unless you have verified that your setup is not
754 affected by entries in the DMI blacklist. Required by PNP
755 BIOS code.
756
757 config GART_IOMMU
758 bool "Old AMD GART IOMMU support"
759 select SWIOTLB
760 depends on X86_64 && PCI && AMD_NB
761 ---help---
762 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
763 GART based hardware IOMMUs.
764
765 The GART supports full DMA access for devices with 32-bit access
766 limitations, on systems with more than 3 GB. This is usually needed
767 for USB, sound, many IDE/SATA chipsets and some other devices.
768
769 Newer systems typically have a modern AMD IOMMU, supported via
770 the CONFIG_AMD_IOMMU=y config option.
771
772 In normal configurations this driver is only active when needed:
773 there's more than 3 GB of memory and the system contains a
774 32-bit limited device.
775
776 If unsure, say Y.
777
778 config CALGARY_IOMMU
779 bool "IBM Calgary IOMMU support"
780 select SWIOTLB
781 depends on X86_64 && PCI
782 ---help---
783 Support for hardware IOMMUs in IBM's xSeries x366 and x460
784 systems. Needed to run systems with more than 3GB of memory
785 properly with 32-bit PCI devices that do not support DAC
786 (Double Address Cycle). Calgary also supports bus level
787 isolation, where all DMAs pass through the IOMMU. This
788 prevents them from going anywhere except their intended
789 destination. This catches hard-to-find kernel bugs and
790 mis-behaving drivers and devices that do not use the DMA-API
791 properly to set up their DMA buffers. The IOMMU can be
792 turned off at boot time with the iommu=off parameter.
793 Normally the kernel will make the right choice by itself.
794 If unsure, say Y.
795
796 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
797 def_bool y
798 prompt "Should Calgary be enabled by default?"
799 depends on CALGARY_IOMMU
800 ---help---
801 Should Calgary be enabled by default? if you choose 'y', Calgary
802 will be used (if it exists). If you choose 'n', Calgary will not be
803 used even if it exists. If you choose 'n' and would like to use
804 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
805 If unsure, say Y.
806
807 # need this always selected by IOMMU for the VIA workaround
808 config SWIOTLB
809 def_bool y if X86_64
810 ---help---
811 Support for software bounce buffers used on x86-64 systems
812 which don't have a hardware IOMMU. Using this PCI devices
813 which can only access 32-bits of memory can be used on systems
814 with more than 3 GB of memory.
815 If unsure, say Y.
816
817 config IOMMU_HELPER
818 def_bool y
819 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
820
821 config MAXSMP
822 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
823 depends on X86_64 && SMP && DEBUG_KERNEL
824 select CPUMASK_OFFSTACK
825 ---help---
826 Enable maximum number of CPUS and NUMA Nodes for this architecture.
827 If unsure, say N.
828
829 config NR_CPUS
830 int "Maximum number of CPUs" if SMP && !MAXSMP
831 range 2 8 if SMP && X86_32 && !X86_BIGSMP
832 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
833 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
834 default "1" if !SMP
835 default "8192" if MAXSMP
836 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
837 default "8" if SMP
838 ---help---
839 This allows you to specify the maximum number of CPUs which this
840 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
841 supported value is 4096, otherwise the maximum value is 512. The
842 minimum value which makes sense is 2.
843
844 This is purely to save memory - each supported CPU adds
845 approximately eight kilobytes to the kernel image.
846
847 config SCHED_SMT
848 bool "SMT (Hyperthreading) scheduler support"
849 depends on X86_HT
850 ---help---
851 SMT scheduler support improves the CPU scheduler's decision making
852 when dealing with Intel Pentium 4 chips with HyperThreading at a
853 cost of slightly increased overhead in some places. If unsure say
854 N here.
855
856 config SCHED_MC
857 def_bool y
858 prompt "Multi-core scheduler support"
859 depends on X86_HT
860 ---help---
861 Multi-core scheduler support improves the CPU scheduler's decision
862 making when dealing with multi-core CPU chips at a cost of slightly
863 increased overhead in some places. If unsure say N here.
864
865 source "kernel/Kconfig.preempt"
866
867 config X86_UP_APIC
868 bool "Local APIC support on uniprocessors"
869 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
870 ---help---
871 A local APIC (Advanced Programmable Interrupt Controller) is an
872 integrated interrupt controller in the CPU. If you have a single-CPU
873 system which has a processor with a local APIC, you can say Y here to
874 enable and use it. If you say Y here even though your machine doesn't
875 have a local APIC, then the kernel will still run with no slowdown at
876 all. The local APIC supports CPU-generated self-interrupts (timer,
877 performance counters), and the NMI watchdog which detects hard
878 lockups.
879
880 config X86_UP_IOAPIC
881 bool "IO-APIC support on uniprocessors"
882 depends on X86_UP_APIC
883 ---help---
884 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
885 SMP-capable replacement for PC-style interrupt controllers. Most
886 SMP systems and many recent uniprocessor systems have one.
887
888 If you have a single-CPU system with an IO-APIC, you can say Y here
889 to use it. If you say Y here even though your machine doesn't have
890 an IO-APIC, then the kernel will still run with no slowdown at all.
891
892 config X86_LOCAL_APIC
893 def_bool y
894 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
895
896 config X86_IO_APIC
897 def_bool y
898 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
899
900 config X86_VISWS_APIC
901 def_bool y
902 depends on X86_32 && X86_VISWS
903
904 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
905 bool "Reroute for broken boot IRQs"
906 depends on X86_IO_APIC
907 ---help---
908 This option enables a workaround that fixes a source of
909 spurious interrupts. This is recommended when threaded
910 interrupt handling is used on systems where the generation of
911 superfluous "boot interrupts" cannot be disabled.
912
913 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
914 entry in the chipset's IO-APIC is masked (as, e.g. the RT
915 kernel does during interrupt handling). On chipsets where this
916 boot IRQ generation cannot be disabled, this workaround keeps
917 the original IRQ line masked so that only the equivalent "boot
918 IRQ" is delivered to the CPUs. The workaround also tells the
919 kernel to set up the IRQ handler on the boot IRQ line. In this
920 way only one interrupt is delivered to the kernel. Otherwise
921 the spurious second interrupt may cause the kernel to bring
922 down (vital) interrupt lines.
923
924 Only affects "broken" chipsets. Interrupt sharing may be
925 increased on these systems.
926
927 config X86_MCE
928 bool "Machine Check / overheating reporting"
929 default y
930 ---help---
931 Machine Check support allows the processor to notify the
932 kernel if it detects a problem (e.g. overheating, data corruption).
933 The action the kernel takes depends on the severity of the problem,
934 ranging from warning messages to halting the machine.
935
936 config X86_MCE_INTEL
937 def_bool y
938 prompt "Intel MCE features"
939 depends on X86_MCE && X86_LOCAL_APIC
940 ---help---
941 Additional support for intel specific MCE features such as
942 the thermal monitor.
943
944 config X86_MCE_AMD
945 def_bool y
946 prompt "AMD MCE features"
947 depends on X86_MCE && X86_LOCAL_APIC
948 ---help---
949 Additional support for AMD specific MCE features such as
950 the DRAM Error Threshold.
951
952 config X86_ANCIENT_MCE
953 bool "Support for old Pentium 5 / WinChip machine checks"
954 depends on X86_32 && X86_MCE
955 ---help---
956 Include support for machine check handling on old Pentium 5 or WinChip
957 systems. These typically need to be enabled explicitely on the command
958 line.
959
960 config X86_MCE_THRESHOLD
961 depends on X86_MCE_AMD || X86_MCE_INTEL
962 def_bool y
963
964 config X86_MCE_INJECT
965 depends on X86_MCE
966 tristate "Machine check injector support"
967 ---help---
968 Provide support for injecting machine checks for testing purposes.
969 If you don't know what a machine check is and you don't do kernel
970 QA it is safe to say n.
971
972 config X86_THERMAL_VECTOR
973 def_bool y
974 depends on X86_MCE_INTEL
975
976 config VM86
977 bool "Enable VM86 support" if EXPERT
978 default y
979 depends on X86_32
980 ---help---
981 This option is required by programs like DOSEMU to run 16-bit legacy
982 code on X86 processors. It also may be needed by software like
983 XFree86 to initialize some video cards via BIOS. Disabling this
984 option saves about 6k.
985
986 config TOSHIBA
987 tristate "Toshiba Laptop support"
988 depends on X86_32
989 ---help---
990 This adds a driver to safely access the System Management Mode of
991 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
992 not work on models with a Phoenix BIOS. The System Management Mode
993 is used to set the BIOS and power saving options on Toshiba portables.
994
995 For information on utilities to make use of this driver see the
996 Toshiba Linux utilities web site at:
997 <http://www.buzzard.org.uk/toshiba/>.
998
999 Say Y if you intend to run this kernel on a Toshiba portable.
1000 Say N otherwise.
1001
1002 config I8K
1003 tristate "Dell laptop support"
1004 select HWMON
1005 ---help---
1006 This adds a driver to safely access the System Management Mode
1007 of the CPU on the Dell Inspiron 8000. The System Management Mode
1008 is used to read cpu temperature and cooling fan status and to
1009 control the fans on the I8K portables.
1010
1011 This driver has been tested only on the Inspiron 8000 but it may
1012 also work with other Dell laptops. You can force loading on other
1013 models by passing the parameter `force=1' to the module. Use at
1014 your own risk.
1015
1016 For information on utilities to make use of this driver see the
1017 I8K Linux utilities web site at:
1018 <http://people.debian.org/~dz/i8k/>
1019
1020 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1021 Say N otherwise.
1022
1023 config X86_REBOOTFIXUPS
1024 bool "Enable X86 board specific fixups for reboot"
1025 depends on X86_32
1026 ---help---
1027 This enables chipset and/or board specific fixups to be done
1028 in order to get reboot to work correctly. This is only needed on
1029 some combinations of hardware and BIOS. The symptom, for which
1030 this config is intended, is when reboot ends with a stalled/hung
1031 system.
1032
1033 Currently, the only fixup is for the Geode machines using
1034 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1035
1036 Say Y if you want to enable the fixup. Currently, it's safe to
1037 enable this option even if you don't need it.
1038 Say N otherwise.
1039
1040 config MICROCODE
1041 tristate "CPU microcode loading support"
1042 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1043 select FW_LOADER
1044 ---help---
1045
1046 If you say Y here, you will be able to update the microcode on
1047 certain Intel and AMD processors. The Intel support is for the
1048 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1049 Xeon etc. The AMD support is for families 0x10 and later. You will
1050 obviously need the actual microcode binary data itself which is not
1051 shipped with the Linux kernel.
1052
1053 This option selects the general module only, you need to select
1054 at least one vendor specific module as well.
1055
1056 To compile this driver as a module, choose M here: the module
1057 will be called microcode.
1058
1059 config MICROCODE_INTEL
1060 bool "Intel microcode loading support"
1061 depends on MICROCODE
1062 default MICROCODE
1063 select FW_LOADER
1064 ---help---
1065 This options enables microcode patch loading support for Intel
1066 processors.
1067
1068 For latest news and information on obtaining all the required
1069 Intel ingredients for this driver, check:
1070 <http://www.urbanmyth.org/microcode/>.
1071
1072 config MICROCODE_AMD
1073 bool "AMD microcode loading support"
1074 depends on MICROCODE
1075 select FW_LOADER
1076 ---help---
1077 If you select this option, microcode patch loading support for AMD
1078 processors will be enabled.
1079
1080 config MICROCODE_OLD_INTERFACE
1081 def_bool y
1082 depends on MICROCODE
1083
1084 config MICROCODE_INTEL_LIB
1085 def_bool y
1086 depends on MICROCODE_INTEL
1087
1088 config MICROCODE_INTEL_EARLY
1089 def_bool n
1090
1091 config MICROCODE_AMD_EARLY
1092 def_bool n
1093
1094 config MICROCODE_EARLY
1095 bool "Early load microcode"
1096 depends on MICROCODE=y && BLK_DEV_INITRD
1097 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1098 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1099 default y
1100 help
1101 This option provides functionality to read additional microcode data
1102 at the beginning of initrd image. The data tells kernel to load
1103 microcode to CPU's as early as possible. No functional change if no
1104 microcode data is glued to the initrd, therefore it's safe to say Y.
1105
1106 config X86_MSR
1107 tristate "/dev/cpu/*/msr - Model-specific register support"
1108 ---help---
1109 This device gives privileged processes access to the x86
1110 Model-Specific Registers (MSRs). It is a character device with
1111 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1112 MSR accesses are directed to a specific CPU on multi-processor
1113 systems.
1114
1115 config X86_CPUID
1116 tristate "/dev/cpu/*/cpuid - CPU information support"
1117 ---help---
1118 This device gives processes access to the x86 CPUID instruction to
1119 be executed on a specific processor. It is a character device
1120 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1121 /dev/cpu/31/cpuid.
1122
1123 choice
1124 prompt "High Memory Support"
1125 default HIGHMEM64G if X86_NUMAQ
1126 default HIGHMEM4G
1127 depends on X86_32
1128
1129 config NOHIGHMEM
1130 bool "off"
1131 depends on !X86_NUMAQ
1132 ---help---
1133 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1134 However, the address space of 32-bit x86 processors is only 4
1135 Gigabytes large. That means that, if you have a large amount of
1136 physical memory, not all of it can be "permanently mapped" by the
1137 kernel. The physical memory that's not permanently mapped is called
1138 "high memory".
1139
1140 If you are compiling a kernel which will never run on a machine with
1141 more than 1 Gigabyte total physical RAM, answer "off" here (default
1142 choice and suitable for most users). This will result in a "3GB/1GB"
1143 split: 3GB are mapped so that each process sees a 3GB virtual memory
1144 space and the remaining part of the 4GB virtual memory space is used
1145 by the kernel to permanently map as much physical memory as
1146 possible.
1147
1148 If the machine has between 1 and 4 Gigabytes physical RAM, then
1149 answer "4GB" here.
1150
1151 If more than 4 Gigabytes is used then answer "64GB" here. This
1152 selection turns Intel PAE (Physical Address Extension) mode on.
1153 PAE implements 3-level paging on IA32 processors. PAE is fully
1154 supported by Linux, PAE mode is implemented on all recent Intel
1155 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1156 then the kernel will not boot on CPUs that don't support PAE!
1157
1158 The actual amount of total physical memory will either be
1159 auto detected or can be forced by using a kernel command line option
1160 such as "mem=256M". (Try "man bootparam" or see the documentation of
1161 your boot loader (lilo or loadlin) about how to pass options to the
1162 kernel at boot time.)
1163
1164 If unsure, say "off".
1165
1166 config HIGHMEM4G
1167 bool "4GB"
1168 depends on !X86_NUMAQ
1169 ---help---
1170 Select this if you have a 32-bit processor and between 1 and 4
1171 gigabytes of physical RAM.
1172
1173 config HIGHMEM64G
1174 bool "64GB"
1175 depends on !M486
1176 select X86_PAE
1177 ---help---
1178 Select this if you have a 32-bit processor and more than 4
1179 gigabytes of physical RAM.
1180
1181 endchoice
1182
1183 choice
1184 prompt "Memory split" if EXPERT
1185 default VMSPLIT_3G
1186 depends on X86_32
1187 ---help---
1188 Select the desired split between kernel and user memory.
1189
1190 If the address range available to the kernel is less than the
1191 physical memory installed, the remaining memory will be available
1192 as "high memory". Accessing high memory is a little more costly
1193 than low memory, as it needs to be mapped into the kernel first.
1194 Note that increasing the kernel address space limits the range
1195 available to user programs, making the address space there
1196 tighter. Selecting anything other than the default 3G/1G split
1197 will also likely make your kernel incompatible with binary-only
1198 kernel modules.
1199
1200 If you are not absolutely sure what you are doing, leave this
1201 option alone!
1202
1203 config VMSPLIT_3G
1204 bool "3G/1G user/kernel split"
1205 config VMSPLIT_3G_OPT
1206 depends on !X86_PAE
1207 bool "3G/1G user/kernel split (for full 1G low memory)"
1208 config VMSPLIT_2G
1209 bool "2G/2G user/kernel split"
1210 config VMSPLIT_2G_OPT
1211 depends on !X86_PAE
1212 bool "2G/2G user/kernel split (for full 2G low memory)"
1213 config VMSPLIT_1G
1214 bool "1G/3G user/kernel split"
1215 endchoice
1216
1217 config PAGE_OFFSET
1218 hex
1219 default 0xB0000000 if VMSPLIT_3G_OPT
1220 default 0x80000000 if VMSPLIT_2G
1221 default 0x78000000 if VMSPLIT_2G_OPT
1222 default 0x40000000 if VMSPLIT_1G
1223 default 0xC0000000
1224 depends on X86_32
1225
1226 config HIGHMEM
1227 def_bool y
1228 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1229
1230 config X86_PAE
1231 bool "PAE (Physical Address Extension) Support"
1232 depends on X86_32 && !HIGHMEM4G
1233 ---help---
1234 PAE is required for NX support, and furthermore enables
1235 larger swapspace support for non-overcommit purposes. It
1236 has the cost of more pagetable lookup overhead, and also
1237 consumes more pagetable space per process.
1238
1239 config ARCH_PHYS_ADDR_T_64BIT
1240 def_bool y
1241 depends on X86_64 || X86_PAE
1242
1243 config ARCH_DMA_ADDR_T_64BIT
1244 def_bool y
1245 depends on X86_64 || HIGHMEM64G
1246
1247 config DIRECT_GBPAGES
1248 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1249 default y
1250 depends on X86_64
1251 ---help---
1252 Allow the kernel linear mapping to use 1GB pages on CPUs that
1253 support it. This can improve the kernel's performance a tiny bit by
1254 reducing TLB pressure. If in doubt, say "Y".
1255
1256 # Common NUMA Features
1257 config NUMA
1258 bool "Numa Memory Allocation and Scheduler Support"
1259 depends on SMP
1260 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1261 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1262 ---help---
1263 Enable NUMA (Non Uniform Memory Access) support.
1264
1265 The kernel will try to allocate memory used by a CPU on the
1266 local memory controller of the CPU and add some more
1267 NUMA awareness to the kernel.
1268
1269 For 64-bit this is recommended if the system is Intel Core i7
1270 (or later), AMD Opteron, or EM64T NUMA.
1271
1272 For 32-bit this is only needed on (rare) 32-bit-only platforms
1273 that support NUMA topologies, such as NUMAQ / Summit, or if you
1274 boot a 32-bit kernel on a 64-bit NUMA platform.
1275
1276 Otherwise, you should say N.
1277
1278 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1279 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1280
1281 config AMD_NUMA
1282 def_bool y
1283 prompt "Old style AMD Opteron NUMA detection"
1284 depends on X86_64 && NUMA && PCI
1285 ---help---
1286 Enable AMD NUMA node topology detection. You should say Y here if
1287 you have a multi processor AMD system. This uses an old method to
1288 read the NUMA configuration directly from the builtin Northbridge
1289 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1290 which also takes priority if both are compiled in.
1291
1292 config X86_64_ACPI_NUMA
1293 def_bool y
1294 prompt "ACPI NUMA detection"
1295 depends on X86_64 && NUMA && ACPI && PCI
1296 select ACPI_NUMA
1297 ---help---
1298 Enable ACPI SRAT based node topology detection.
1299
1300 # Some NUMA nodes have memory ranges that span
1301 # other nodes. Even though a pfn is valid and
1302 # between a node's start and end pfns, it may not
1303 # reside on that node. See memmap_init_zone()
1304 # for details.
1305 config NODES_SPAN_OTHER_NODES
1306 def_bool y
1307 depends on X86_64_ACPI_NUMA
1308
1309 config NUMA_EMU
1310 bool "NUMA emulation"
1311 depends on NUMA
1312 ---help---
1313 Enable NUMA emulation. A flat machine will be split
1314 into virtual nodes when booted with "numa=fake=N", where N is the
1315 number of nodes. This is only useful for debugging.
1316
1317 config NODES_SHIFT
1318 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1319 range 1 10
1320 default "10" if MAXSMP
1321 default "6" if X86_64
1322 default "4" if X86_NUMAQ
1323 default "3"
1324 depends on NEED_MULTIPLE_NODES
1325 ---help---
1326 Specify the maximum number of NUMA Nodes available on the target
1327 system. Increases memory reserved to accommodate various tables.
1328
1329 config ARCH_HAVE_MEMORY_PRESENT
1330 def_bool y
1331 depends on X86_32 && DISCONTIGMEM
1332
1333 config NEED_NODE_MEMMAP_SIZE
1334 def_bool y
1335 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1336
1337 config ARCH_FLATMEM_ENABLE
1338 def_bool y
1339 depends on X86_32 && !NUMA
1340
1341 config ARCH_DISCONTIGMEM_ENABLE
1342 def_bool y
1343 depends on NUMA && X86_32
1344
1345 config ARCH_DISCONTIGMEM_DEFAULT
1346 def_bool y
1347 depends on NUMA && X86_32
1348
1349 config ARCH_SPARSEMEM_ENABLE
1350 def_bool y
1351 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1352 select SPARSEMEM_STATIC if X86_32
1353 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1354
1355 config ARCH_SPARSEMEM_DEFAULT
1356 def_bool y
1357 depends on X86_64
1358
1359 config ARCH_SELECT_MEMORY_MODEL
1360 def_bool y
1361 depends on ARCH_SPARSEMEM_ENABLE
1362
1363 config ARCH_MEMORY_PROBE
1364 bool "Enable sysfs memory/probe interface"
1365 depends on X86_64 && MEMORY_HOTPLUG
1366 help
1367 This option enables a sysfs memory/probe interface for testing.
1368 See Documentation/memory-hotplug.txt for more information.
1369 If you are unsure how to answer this question, answer N.
1370
1371 config ARCH_PROC_KCORE_TEXT
1372 def_bool y
1373 depends on X86_64 && PROC_KCORE
1374
1375 config ILLEGAL_POINTER_VALUE
1376 hex
1377 default 0 if X86_32
1378 default 0xdead000000000000 if X86_64
1379
1380 source "mm/Kconfig"
1381
1382 config HIGHPTE
1383 bool "Allocate 3rd-level pagetables from highmem"
1384 depends on HIGHMEM
1385 ---help---
1386 The VM uses one page table entry for each page of physical memory.
1387 For systems with a lot of RAM, this can be wasteful of precious
1388 low memory. Setting this option will put user-space page table
1389 entries in high memory.
1390
1391 config X86_CHECK_BIOS_CORRUPTION
1392 bool "Check for low memory corruption"
1393 ---help---
1394 Periodically check for memory corruption in low memory, which
1395 is suspected to be caused by BIOS. Even when enabled in the
1396 configuration, it is disabled at runtime. Enable it by
1397 setting "memory_corruption_check=1" on the kernel command
1398 line. By default it scans the low 64k of memory every 60
1399 seconds; see the memory_corruption_check_size and
1400 memory_corruption_check_period parameters in
1401 Documentation/kernel-parameters.txt to adjust this.
1402
1403 When enabled with the default parameters, this option has
1404 almost no overhead, as it reserves a relatively small amount
1405 of memory and scans it infrequently. It both detects corruption
1406 and prevents it from affecting the running system.
1407
1408 It is, however, intended as a diagnostic tool; if repeatable
1409 BIOS-originated corruption always affects the same memory,
1410 you can use memmap= to prevent the kernel from using that
1411 memory.
1412
1413 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1414 bool "Set the default setting of memory_corruption_check"
1415 depends on X86_CHECK_BIOS_CORRUPTION
1416 default y
1417 ---help---
1418 Set whether the default state of memory_corruption_check is
1419 on or off.
1420
1421 config X86_RESERVE_LOW
1422 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1423 default 64
1424 range 4 640
1425 ---help---
1426 Specify the amount of low memory to reserve for the BIOS.
1427
1428 The first page contains BIOS data structures that the kernel
1429 must not use, so that page must always be reserved.
1430
1431 By default we reserve the first 64K of physical RAM, as a
1432 number of BIOSes are known to corrupt that memory range
1433 during events such as suspend/resume or monitor cable
1434 insertion, so it must not be used by the kernel.
1435
1436 You can set this to 4 if you are absolutely sure that you
1437 trust the BIOS to get all its memory reservations and usages
1438 right. If you know your BIOS have problems beyond the
1439 default 64K area, you can set this to 640 to avoid using the
1440 entire low memory range.
1441
1442 If you have doubts about the BIOS (e.g. suspend/resume does
1443 not work or there's kernel crashes after certain hardware
1444 hotplug events) then you might want to enable
1445 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1446 typical corruption patterns.
1447
1448 Leave this to the default value of 64 if you are unsure.
1449
1450 config MATH_EMULATION
1451 bool
1452 prompt "Math emulation" if X86_32
1453 ---help---
1454 Linux can emulate a math coprocessor (used for floating point
1455 operations) if you don't have one. 486DX and Pentium processors have
1456 a math coprocessor built in, 486SX and 386 do not, unless you added
1457 a 487DX or 387, respectively. (The messages during boot time can
1458 give you some hints here ["man dmesg"].) Everyone needs either a
1459 coprocessor or this emulation.
1460
1461 If you don't have a math coprocessor, you need to say Y here; if you
1462 say Y here even though you have a coprocessor, the coprocessor will
1463 be used nevertheless. (This behavior can be changed with the kernel
1464 command line option "no387", which comes handy if your coprocessor
1465 is broken. Try "man bootparam" or see the documentation of your boot
1466 loader (lilo or loadlin) about how to pass options to the kernel at
1467 boot time.) This means that it is a good idea to say Y here if you
1468 intend to use this kernel on different machines.
1469
1470 More information about the internals of the Linux math coprocessor
1471 emulation can be found in <file:arch/x86/math-emu/README>.
1472
1473 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1474 kernel, it won't hurt.
1475
1476 config MTRR
1477 def_bool y
1478 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1479 ---help---
1480 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1481 the Memory Type Range Registers (MTRRs) may be used to control
1482 processor access to memory ranges. This is most useful if you have
1483 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1484 allows bus write transfers to be combined into a larger transfer
1485 before bursting over the PCI/AGP bus. This can increase performance
1486 of image write operations 2.5 times or more. Saying Y here creates a
1487 /proc/mtrr file which may be used to manipulate your processor's
1488 MTRRs. Typically the X server should use this.
1489
1490 This code has a reasonably generic interface so that similar
1491 control registers on other processors can be easily supported
1492 as well:
1493
1494 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1495 Registers (ARRs) which provide a similar functionality to MTRRs. For
1496 these, the ARRs are used to emulate the MTRRs.
1497 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1498 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1499 write-combining. All of these processors are supported by this code
1500 and it makes sense to say Y here if you have one of them.
1501
1502 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1503 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1504 can lead to all sorts of problems, so it's good to say Y here.
1505
1506 You can safely say Y even if your machine doesn't have MTRRs, you'll
1507 just add about 9 KB to your kernel.
1508
1509 See <file:Documentation/x86/mtrr.txt> for more information.
1510
1511 config MTRR_SANITIZER
1512 def_bool y
1513 prompt "MTRR cleanup support"
1514 depends on MTRR
1515 ---help---
1516 Convert MTRR layout from continuous to discrete, so X drivers can
1517 add writeback entries.
1518
1519 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1520 The largest mtrr entry size for a continuous block can be set with
1521 mtrr_chunk_size.
1522
1523 If unsure, say Y.
1524
1525 config MTRR_SANITIZER_ENABLE_DEFAULT
1526 int "MTRR cleanup enable value (0-1)"
1527 range 0 1
1528 default "0"
1529 depends on MTRR_SANITIZER
1530 ---help---
1531 Enable mtrr cleanup default value
1532
1533 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1534 int "MTRR cleanup spare reg num (0-7)"
1535 range 0 7
1536 default "1"
1537 depends on MTRR_SANITIZER
1538 ---help---
1539 mtrr cleanup spare entries default, it can be changed via
1540 mtrr_spare_reg_nr=N on the kernel command line.
1541
1542 config X86_PAT
1543 def_bool y
1544 prompt "x86 PAT support" if EXPERT
1545 depends on MTRR
1546 ---help---
1547 Use PAT attributes to setup page level cache control.
1548
1549 PATs are the modern equivalents of MTRRs and are much more
1550 flexible than MTRRs.
1551
1552 Say N here if you see bootup problems (boot crash, boot hang,
1553 spontaneous reboots) or a non-working video driver.
1554
1555 If unsure, say Y.
1556
1557 config ARCH_USES_PG_UNCACHED
1558 def_bool y
1559 depends on X86_PAT
1560
1561 config ARCH_RANDOM
1562 def_bool y
1563 prompt "x86 architectural random number generator" if EXPERT
1564 ---help---
1565 Enable the x86 architectural RDRAND instruction
1566 (Intel Bull Mountain technology) to generate random numbers.
1567 If supported, this is a high bandwidth, cryptographically
1568 secure hardware random number generator.
1569
1570 config X86_SMAP
1571 def_bool y
1572 prompt "Supervisor Mode Access Prevention" if EXPERT
1573 ---help---
1574 Supervisor Mode Access Prevention (SMAP) is a security
1575 feature in newer Intel processors. There is a small
1576 performance cost if this enabled and turned on; there is
1577 also a small increase in the kernel size if this is enabled.
1578
1579 If unsure, say Y.
1580
1581 config EFI
1582 bool "EFI runtime service support"
1583 depends on ACPI
1584 select UCS2_STRING
1585 ---help---
1586 This enables the kernel to use EFI runtime services that are
1587 available (such as the EFI variable services).
1588
1589 This option is only useful on systems that have EFI firmware.
1590 In addition, you should use the latest ELILO loader available
1591 at <http://elilo.sourceforge.net> in order to take advantage
1592 of EFI runtime services. However, even with this option, the
1593 resultant kernel should continue to boot on existing non-EFI
1594 platforms.
1595
1596 config EFI_STUB
1597 bool "EFI stub support"
1598 depends on EFI
1599 ---help---
1600 This kernel feature allows a bzImage to be loaded directly
1601 by EFI firmware without the use of a bootloader.
1602
1603 See Documentation/efi-stub.txt for more information.
1604
1605 config SECCOMP
1606 def_bool y
1607 prompt "Enable seccomp to safely compute untrusted bytecode"
1608 ---help---
1609 This kernel feature is useful for number crunching applications
1610 that may need to compute untrusted bytecode during their
1611 execution. By using pipes or other transports made available to
1612 the process as file descriptors supporting the read/write
1613 syscalls, it's possible to isolate those applications in
1614 their own address space using seccomp. Once seccomp is
1615 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1616 and the task is only allowed to execute a few safe syscalls
1617 defined by each seccomp mode.
1618
1619 If unsure, say Y. Only embedded should say N here.
1620
1621 source kernel/Kconfig.hz
1622
1623 config KEXEC
1624 bool "kexec system call"
1625 ---help---
1626 kexec is a system call that implements the ability to shutdown your
1627 current kernel, and to start another kernel. It is like a reboot
1628 but it is independent of the system firmware. And like a reboot
1629 you can start any kernel with it, not just Linux.
1630
1631 The name comes from the similarity to the exec system call.
1632
1633 It is an ongoing process to be certain the hardware in a machine
1634 is properly shutdown, so do not be surprised if this code does not
1635 initially work for you. As of this writing the exact hardware
1636 interface is strongly in flux, so no good recommendation can be
1637 made.
1638
1639 config CRASH_DUMP
1640 bool "kernel crash dumps"
1641 depends on X86_64 || (X86_32 && HIGHMEM)
1642 ---help---
1643 Generate crash dump after being started by kexec.
1644 This should be normally only set in special crash dump kernels
1645 which are loaded in the main kernel with kexec-tools into
1646 a specially reserved region and then later executed after
1647 a crash by kdump/kexec. The crash dump kernel must be compiled
1648 to a memory address not used by the main kernel or BIOS using
1649 PHYSICAL_START, or it must be built as a relocatable image
1650 (CONFIG_RELOCATABLE=y).
1651 For more details see Documentation/kdump/kdump.txt
1652
1653 config KEXEC_JUMP
1654 bool "kexec jump"
1655 depends on KEXEC && HIBERNATION
1656 ---help---
1657 Jump between original kernel and kexeced kernel and invoke
1658 code in physical address mode via KEXEC
1659
1660 config PHYSICAL_START
1661 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1662 default "0x1000000"
1663 ---help---
1664 This gives the physical address where the kernel is loaded.
1665
1666 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1667 bzImage will decompress itself to above physical address and
1668 run from there. Otherwise, bzImage will run from the address where
1669 it has been loaded by the boot loader and will ignore above physical
1670 address.
1671
1672 In normal kdump cases one does not have to set/change this option
1673 as now bzImage can be compiled as a completely relocatable image
1674 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1675 address. This option is mainly useful for the folks who don't want
1676 to use a bzImage for capturing the crash dump and want to use a
1677 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1678 to be specifically compiled to run from a specific memory area
1679 (normally a reserved region) and this option comes handy.
1680
1681 So if you are using bzImage for capturing the crash dump,
1682 leave the value here unchanged to 0x1000000 and set
1683 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1684 for capturing the crash dump change this value to start of
1685 the reserved region. In other words, it can be set based on
1686 the "X" value as specified in the "crashkernel=YM@XM"
1687 command line boot parameter passed to the panic-ed
1688 kernel. Please take a look at Documentation/kdump/kdump.txt
1689 for more details about crash dumps.
1690
1691 Usage of bzImage for capturing the crash dump is recommended as
1692 one does not have to build two kernels. Same kernel can be used
1693 as production kernel and capture kernel. Above option should have
1694 gone away after relocatable bzImage support is introduced. But it
1695 is present because there are users out there who continue to use
1696 vmlinux for dump capture. This option should go away down the
1697 line.
1698
1699 Don't change this unless you know what you are doing.
1700
1701 config RELOCATABLE
1702 bool "Build a relocatable kernel"
1703 default y
1704 ---help---
1705 This builds a kernel image that retains relocation information
1706 so it can be loaded someplace besides the default 1MB.
1707 The relocations tend to make the kernel binary about 10% larger,
1708 but are discarded at runtime.
1709
1710 One use is for the kexec on panic case where the recovery kernel
1711 must live at a different physical address than the primary
1712 kernel.
1713
1714 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1715 it has been loaded at and the compile time physical address
1716 (CONFIG_PHYSICAL_START) is ignored.
1717
1718 # Relocation on x86-32 needs some additional build support
1719 config X86_NEED_RELOCS
1720 def_bool y
1721 depends on X86_32 && RELOCATABLE
1722
1723 config PHYSICAL_ALIGN
1724 hex "Alignment value to which kernel should be aligned"
1725 default "0x1000000"
1726 range 0x2000 0x1000000 if X86_32
1727 range 0x200000 0x1000000 if X86_64
1728 ---help---
1729 This value puts the alignment restrictions on physical address
1730 where kernel is loaded and run from. Kernel is compiled for an
1731 address which meets above alignment restriction.
1732
1733 If bootloader loads the kernel at a non-aligned address and
1734 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1735 address aligned to above value and run from there.
1736
1737 If bootloader loads the kernel at a non-aligned address and
1738 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1739 load address and decompress itself to the address it has been
1740 compiled for and run from there. The address for which kernel is
1741 compiled already meets above alignment restrictions. Hence the
1742 end result is that kernel runs from a physical address meeting
1743 above alignment restrictions.
1744
1745 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1746 this value must be a multiple of 0x200000.
1747
1748 Don't change this unless you know what you are doing.
1749
1750 config HOTPLUG_CPU
1751 bool "Support for hot-pluggable CPUs"
1752 depends on SMP
1753 ---help---
1754 Say Y here to allow turning CPUs off and on. CPUs can be
1755 controlled through /sys/devices/system/cpu.
1756 ( Note: power management support will enable this option
1757 automatically on SMP systems. )
1758 Say N if you want to disable CPU hotplug.
1759
1760 config BOOTPARAM_HOTPLUG_CPU0
1761 bool "Set default setting of cpu0_hotpluggable"
1762 default n
1763 depends on HOTPLUG_CPU
1764 ---help---
1765 Set whether default state of cpu0_hotpluggable is on or off.
1766
1767 Say Y here to enable CPU0 hotplug by default. If this switch
1768 is turned on, there is no need to give cpu0_hotplug kernel
1769 parameter and the CPU0 hotplug feature is enabled by default.
1770
1771 Please note: there are two known CPU0 dependencies if you want
1772 to enable the CPU0 hotplug feature either by this switch or by
1773 cpu0_hotplug kernel parameter.
1774
1775 First, resume from hibernate or suspend always starts from CPU0.
1776 So hibernate and suspend are prevented if CPU0 is offline.
1777
1778 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1779 offline if any interrupt can not migrate out of CPU0. There may
1780 be other CPU0 dependencies.
1781
1782 Please make sure the dependencies are under your control before
1783 you enable this feature.
1784
1785 Say N if you don't want to enable CPU0 hotplug feature by default.
1786 You still can enable the CPU0 hotplug feature at boot by kernel
1787 parameter cpu0_hotplug.
1788
1789 config DEBUG_HOTPLUG_CPU0
1790 def_bool n
1791 prompt "Debug CPU0 hotplug"
1792 depends on HOTPLUG_CPU
1793 ---help---
1794 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1795 soon as possible and boots up userspace with CPU0 offlined. User
1796 can online CPU0 back after boot time.
1797
1798 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1799 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1800 compilation or giving cpu0_hotplug kernel parameter at boot.
1801
1802 If unsure, say N.
1803
1804 config COMPAT_VDSO
1805 def_bool y
1806 prompt "Compat VDSO support"
1807 depends on X86_32 || IA32_EMULATION
1808 ---help---
1809 Map the 32-bit VDSO to the predictable old-style address too.
1810
1811 Say N here if you are running a sufficiently recent glibc
1812 version (2.3.3 or later), to remove the high-mapped
1813 VDSO mapping and to exclusively use the randomized VDSO.
1814
1815 If unsure, say Y.
1816
1817 config CMDLINE_BOOL
1818 bool "Built-in kernel command line"
1819 ---help---
1820 Allow for specifying boot arguments to the kernel at
1821 build time. On some systems (e.g. embedded ones), it is
1822 necessary or convenient to provide some or all of the
1823 kernel boot arguments with the kernel itself (that is,
1824 to not rely on the boot loader to provide them.)
1825
1826 To compile command line arguments into the kernel,
1827 set this option to 'Y', then fill in the
1828 the boot arguments in CONFIG_CMDLINE.
1829
1830 Systems with fully functional boot loaders (i.e. non-embedded)
1831 should leave this option set to 'N'.
1832
1833 config CMDLINE
1834 string "Built-in kernel command string"
1835 depends on CMDLINE_BOOL
1836 default ""
1837 ---help---
1838 Enter arguments here that should be compiled into the kernel
1839 image and used at boot time. If the boot loader provides a
1840 command line at boot time, it is appended to this string to
1841 form the full kernel command line, when the system boots.
1842
1843 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1844 change this behavior.
1845
1846 In most cases, the command line (whether built-in or provided
1847 by the boot loader) should specify the device for the root
1848 file system.
1849
1850 config CMDLINE_OVERRIDE
1851 bool "Built-in command line overrides boot loader arguments"
1852 depends on CMDLINE_BOOL
1853 ---help---
1854 Set this option to 'Y' to have the kernel ignore the boot loader
1855 command line, and use ONLY the built-in command line.
1856
1857 This is used to work around broken boot loaders. This should
1858 be set to 'N' under normal conditions.
1859
1860 endmenu
1861
1862 config ARCH_ENABLE_MEMORY_HOTPLUG
1863 def_bool y
1864 depends on X86_64 || (X86_32 && HIGHMEM)
1865
1866 config ARCH_ENABLE_MEMORY_HOTREMOVE
1867 def_bool y
1868 depends on MEMORY_HOTPLUG
1869
1870 config USE_PERCPU_NUMA_NODE_ID
1871 def_bool y
1872 depends on NUMA
1873
1874 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1875 def_bool y
1876 depends on X86_64 || X86_PAE
1877
1878 menu "Power management and ACPI options"
1879
1880 config ARCH_HIBERNATION_HEADER
1881 def_bool y
1882 depends on X86_64 && HIBERNATION
1883
1884 source "kernel/power/Kconfig"
1885
1886 source "drivers/acpi/Kconfig"
1887
1888 source "drivers/sfi/Kconfig"
1889
1890 config X86_APM_BOOT
1891 def_bool y
1892 depends on APM
1893
1894 menuconfig APM
1895 tristate "APM (Advanced Power Management) BIOS support"
1896 depends on X86_32 && PM_SLEEP
1897 ---help---
1898 APM is a BIOS specification for saving power using several different
1899 techniques. This is mostly useful for battery powered laptops with
1900 APM compliant BIOSes. If you say Y here, the system time will be
1901 reset after a RESUME operation, the /proc/apm device will provide
1902 battery status information, and user-space programs will receive
1903 notification of APM "events" (e.g. battery status change).
1904
1905 If you select "Y" here, you can disable actual use of the APM
1906 BIOS by passing the "apm=off" option to the kernel at boot time.
1907
1908 Note that the APM support is almost completely disabled for
1909 machines with more than one CPU.
1910
1911 In order to use APM, you will need supporting software. For location
1912 and more information, read <file:Documentation/power/apm-acpi.txt>
1913 and the Battery Powered Linux mini-HOWTO, available from
1914 <http://www.tldp.org/docs.html#howto>.
1915
1916 This driver does not spin down disk drives (see the hdparm(8)
1917 manpage ("man 8 hdparm") for that), and it doesn't turn off
1918 VESA-compliant "green" monitors.
1919
1920 This driver does not support the TI 4000M TravelMate and the ACER
1921 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1922 desktop machines also don't have compliant BIOSes, and this driver
1923 may cause those machines to panic during the boot phase.
1924
1925 Generally, if you don't have a battery in your machine, there isn't
1926 much point in using this driver and you should say N. If you get
1927 random kernel OOPSes or reboots that don't seem to be related to
1928 anything, try disabling/enabling this option (or disabling/enabling
1929 APM in your BIOS).
1930
1931 Some other things you should try when experiencing seemingly random,
1932 "weird" problems:
1933
1934 1) make sure that you have enough swap space and that it is
1935 enabled.
1936 2) pass the "no-hlt" option to the kernel
1937 3) switch on floating point emulation in the kernel and pass
1938 the "no387" option to the kernel
1939 4) pass the "floppy=nodma" option to the kernel
1940 5) pass the "mem=4M" option to the kernel (thereby disabling
1941 all but the first 4 MB of RAM)
1942 6) make sure that the CPU is not over clocked.
1943 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1944 8) disable the cache from your BIOS settings
1945 9) install a fan for the video card or exchange video RAM
1946 10) install a better fan for the CPU
1947 11) exchange RAM chips
1948 12) exchange the motherboard.
1949
1950 To compile this driver as a module, choose M here: the
1951 module will be called apm.
1952
1953 if APM
1954
1955 config APM_IGNORE_USER_SUSPEND
1956 bool "Ignore USER SUSPEND"
1957 ---help---
1958 This option will ignore USER SUSPEND requests. On machines with a
1959 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1960 series notebooks, it is necessary to say Y because of a BIOS bug.
1961
1962 config APM_DO_ENABLE
1963 bool "Enable PM at boot time"
1964 ---help---
1965 Enable APM features at boot time. From page 36 of the APM BIOS
1966 specification: "When disabled, the APM BIOS does not automatically
1967 power manage devices, enter the Standby State, enter the Suspend
1968 State, or take power saving steps in response to CPU Idle calls."
1969 This driver will make CPU Idle calls when Linux is idle (unless this
1970 feature is turned off -- see "Do CPU IDLE calls", below). This
1971 should always save battery power, but more complicated APM features
1972 will be dependent on your BIOS implementation. You may need to turn
1973 this option off if your computer hangs at boot time when using APM
1974 support, or if it beeps continuously instead of suspending. Turn
1975 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1976 T400CDT. This is off by default since most machines do fine without
1977 this feature.
1978
1979 config APM_CPU_IDLE
1980 depends on CPU_IDLE
1981 bool "Make CPU Idle calls when idle"
1982 ---help---
1983 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1984 On some machines, this can activate improved power savings, such as
1985 a slowed CPU clock rate, when the machine is idle. These idle calls
1986 are made after the idle loop has run for some length of time (e.g.,
1987 333 mS). On some machines, this will cause a hang at boot time or
1988 whenever the CPU becomes idle. (On machines with more than one CPU,
1989 this option does nothing.)
1990
1991 config APM_DISPLAY_BLANK
1992 bool "Enable console blanking using APM"
1993 ---help---
1994 Enable console blanking using the APM. Some laptops can use this to
1995 turn off the LCD backlight when the screen blanker of the Linux
1996 virtual console blanks the screen. Note that this is only used by
1997 the virtual console screen blanker, and won't turn off the backlight
1998 when using the X Window system. This also doesn't have anything to
1999 do with your VESA-compliant power-saving monitor. Further, this
2000 option doesn't work for all laptops -- it might not turn off your
2001 backlight at all, or it might print a lot of errors to the console,
2002 especially if you are using gpm.
2003
2004 config APM_ALLOW_INTS
2005 bool "Allow interrupts during APM BIOS calls"
2006 ---help---
2007 Normally we disable external interrupts while we are making calls to
2008 the APM BIOS as a measure to lessen the effects of a badly behaving
2009 BIOS implementation. The BIOS should reenable interrupts if it
2010 needs to. Unfortunately, some BIOSes do not -- especially those in
2011 many of the newer IBM Thinkpads. If you experience hangs when you
2012 suspend, try setting this to Y. Otherwise, say N.
2013
2014 endif # APM
2015
2016 source "drivers/cpufreq/Kconfig"
2017
2018 source "drivers/cpuidle/Kconfig"
2019
2020 source "drivers/idle/Kconfig"
2021
2022 endmenu
2023
2024
2025 menu "Bus options (PCI etc.)"
2026
2027 config PCI
2028 bool "PCI support"
2029 default y
2030 ---help---
2031 Find out whether you have a PCI motherboard. PCI is the name of a
2032 bus system, i.e. the way the CPU talks to the other stuff inside
2033 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2034 VESA. If you have PCI, say Y, otherwise N.
2035
2036 choice
2037 prompt "PCI access mode"
2038 depends on X86_32 && PCI
2039 default PCI_GOANY
2040 ---help---
2041 On PCI systems, the BIOS can be used to detect the PCI devices and
2042 determine their configuration. However, some old PCI motherboards
2043 have BIOS bugs and may crash if this is done. Also, some embedded
2044 PCI-based systems don't have any BIOS at all. Linux can also try to
2045 detect the PCI hardware directly without using the BIOS.
2046
2047 With this option, you can specify how Linux should detect the
2048 PCI devices. If you choose "BIOS", the BIOS will be used,
2049 if you choose "Direct", the BIOS won't be used, and if you
2050 choose "MMConfig", then PCI Express MMCONFIG will be used.
2051 If you choose "Any", the kernel will try MMCONFIG, then the
2052 direct access method and falls back to the BIOS if that doesn't
2053 work. If unsure, go with the default, which is "Any".
2054
2055 config PCI_GOBIOS
2056 bool "BIOS"
2057
2058 config PCI_GOMMCONFIG
2059 bool "MMConfig"
2060
2061 config PCI_GODIRECT
2062 bool "Direct"
2063
2064 config PCI_GOOLPC
2065 bool "OLPC XO-1"
2066 depends on OLPC
2067
2068 config PCI_GOANY
2069 bool "Any"
2070
2071 endchoice
2072
2073 config PCI_BIOS
2074 def_bool y
2075 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2076
2077 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2078 config PCI_DIRECT
2079 def_bool y
2080 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2081
2082 config PCI_MMCONFIG
2083 def_bool y
2084 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2085
2086 config PCI_OLPC
2087 def_bool y
2088 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2089
2090 config PCI_XEN
2091 def_bool y
2092 depends on PCI && XEN
2093 select SWIOTLB_XEN
2094
2095 config PCI_DOMAINS
2096 def_bool y
2097 depends on PCI
2098
2099 config PCI_MMCONFIG
2100 bool "Support mmconfig PCI config space access"
2101 depends on X86_64 && PCI && ACPI
2102
2103 config PCI_CNB20LE_QUIRK
2104 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2105 depends on PCI
2106 help
2107 Read the PCI windows out of the CNB20LE host bridge. This allows
2108 PCI hotplug to work on systems with the CNB20LE chipset which do
2109 not have ACPI.
2110
2111 There's no public spec for this chipset, and this functionality
2112 is known to be incomplete.
2113
2114 You should say N unless you know you need this.
2115
2116 source "drivers/pci/pcie/Kconfig"
2117
2118 source "drivers/pci/Kconfig"
2119
2120 # x86_64 have no ISA slots, but can have ISA-style DMA.
2121 config ISA_DMA_API
2122 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2123 default y
2124 help
2125 Enables ISA-style DMA support for devices requiring such controllers.
2126 If unsure, say Y.
2127
2128 if X86_32
2129
2130 config ISA
2131 bool "ISA support"
2132 ---help---
2133 Find out whether you have ISA slots on your motherboard. ISA is the
2134 name of a bus system, i.e. the way the CPU talks to the other stuff
2135 inside your box. Other bus systems are PCI, EISA, MicroChannel
2136 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2137 newer boards don't support it. If you have ISA, say Y, otherwise N.
2138
2139 config EISA
2140 bool "EISA support"
2141 depends on ISA
2142 ---help---
2143 The Extended Industry Standard Architecture (EISA) bus was
2144 developed as an open alternative to the IBM MicroChannel bus.
2145
2146 The EISA bus provided some of the features of the IBM MicroChannel
2147 bus while maintaining backward compatibility with cards made for
2148 the older ISA bus. The EISA bus saw limited use between 1988 and
2149 1995 when it was made obsolete by the PCI bus.
2150
2151 Say Y here if you are building a kernel for an EISA-based machine.
2152
2153 Otherwise, say N.
2154
2155 source "drivers/eisa/Kconfig"
2156
2157 config SCx200
2158 tristate "NatSemi SCx200 support"
2159 ---help---
2160 This provides basic support for National Semiconductor's
2161 (now AMD's) Geode processors. The driver probes for the
2162 PCI-IDs of several on-chip devices, so its a good dependency
2163 for other scx200_* drivers.
2164
2165 If compiled as a module, the driver is named scx200.
2166
2167 config SCx200HR_TIMER
2168 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2169 depends on SCx200
2170 default y
2171 ---help---
2172 This driver provides a clocksource built upon the on-chip
2173 27MHz high-resolution timer. Its also a workaround for
2174 NSC Geode SC-1100's buggy TSC, which loses time when the
2175 processor goes idle (as is done by the scheduler). The
2176 other workaround is idle=poll boot option.
2177
2178 config OLPC
2179 bool "One Laptop Per Child support"
2180 depends on !X86_PAE
2181 select GPIOLIB
2182 select OF
2183 select OF_PROMTREE
2184 select IRQ_DOMAIN
2185 ---help---
2186 Add support for detecting the unique features of the OLPC
2187 XO hardware.
2188
2189 config OLPC_XO1_PM
2190 bool "OLPC XO-1 Power Management"
2191 depends on OLPC && MFD_CS5535 && PM_SLEEP
2192 select MFD_CORE
2193 ---help---
2194 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2195
2196 config OLPC_XO1_RTC
2197 bool "OLPC XO-1 Real Time Clock"
2198 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2199 ---help---
2200 Add support for the XO-1 real time clock, which can be used as a
2201 programmable wakeup source.
2202
2203 config OLPC_XO1_SCI
2204 bool "OLPC XO-1 SCI extras"
2205 depends on OLPC && OLPC_XO1_PM
2206 depends on INPUT=y
2207 select POWER_SUPPLY
2208 select GPIO_CS5535
2209 select MFD_CORE
2210 ---help---
2211 Add support for SCI-based features of the OLPC XO-1 laptop:
2212 - EC-driven system wakeups
2213 - Power button
2214 - Ebook switch
2215 - Lid switch
2216 - AC adapter status updates
2217 - Battery status updates
2218
2219 config OLPC_XO15_SCI
2220 bool "OLPC XO-1.5 SCI extras"
2221 depends on OLPC && ACPI
2222 select POWER_SUPPLY
2223 ---help---
2224 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2225 - EC-driven system wakeups
2226 - AC adapter status updates
2227 - Battery status updates
2228
2229 config ALIX
2230 bool "PCEngines ALIX System Support (LED setup)"
2231 select GPIOLIB
2232 ---help---
2233 This option enables system support for the PCEngines ALIX.
2234 At present this just sets up LEDs for GPIO control on
2235 ALIX2/3/6 boards. However, other system specific setup should
2236 get added here.
2237
2238 Note: You must still enable the drivers for GPIO and LED support
2239 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2240
2241 Note: You have to set alix.force=1 for boards with Award BIOS.
2242
2243 config NET5501
2244 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2245 select GPIOLIB
2246 ---help---
2247 This option enables system support for the Soekris Engineering net5501.
2248
2249 config GEOS
2250 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2251 select GPIOLIB
2252 depends on DMI
2253 ---help---
2254 This option enables system support for the Traverse Technologies GEOS.
2255
2256 config TS5500
2257 bool "Technologic Systems TS-5500 platform support"
2258 depends on MELAN
2259 select CHECK_SIGNATURE
2260 select NEW_LEDS
2261 select LEDS_CLASS
2262 ---help---
2263 This option enables system support for the Technologic Systems TS-5500.
2264
2265 endif # X86_32
2266
2267 config AMD_NB
2268 def_bool y
2269 depends on CPU_SUP_AMD && PCI
2270
2271 source "drivers/pcmcia/Kconfig"
2272
2273 source "drivers/pci/hotplug/Kconfig"
2274
2275 config RAPIDIO
2276 tristate "RapidIO support"
2277 depends on PCI
2278 default n
2279 help
2280 If enabled this option will include drivers and the core
2281 infrastructure code to support RapidIO interconnect devices.
2282
2283 source "drivers/rapidio/Kconfig"
2284
2285 config X86_SYSFB
2286 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2287 help
2288 Firmwares often provide initial graphics framebuffers so the BIOS,
2289 bootloader or kernel can show basic video-output during boot for
2290 user-guidance and debugging. Historically, x86 used the VESA BIOS
2291 Extensions and EFI-framebuffers for this, which are mostly limited
2292 to x86.
2293 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2294 framebuffers so the new generic system-framebuffer drivers can be
2295 used on x86. If the framebuffer is not compatible with the generic
2296 modes, it is adverticed as fallback platform framebuffer so legacy
2297 drivers like efifb, vesafb and uvesafb can pick it up.
2298 If this option is not selected, all system framebuffers are always
2299 marked as fallback platform framebuffers as usual.
2300
2301 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2302 not be able to pick up generic system framebuffers if this option
2303 is selected. You are highly encouraged to enable simplefb as
2304 replacement if you select this option. simplefb can correctly deal
2305 with generic system framebuffers. But you should still keep vesafb
2306 and others enabled as fallback if a system framebuffer is
2307 incompatible with simplefb.
2308
2309 If unsure, say Y.
2310
2311 endmenu
2312
2313
2314 menu "Executable file formats / Emulations"
2315
2316 source "fs/Kconfig.binfmt"
2317
2318 config IA32_EMULATION
2319 bool "IA32 Emulation"
2320 depends on X86_64
2321 select BINFMT_ELF
2322 select COMPAT_BINFMT_ELF
2323 select HAVE_UID16
2324 ---help---
2325 Include code to run legacy 32-bit programs under a
2326 64-bit kernel. You should likely turn this on, unless you're
2327 100% sure that you don't have any 32-bit programs left.
2328
2329 config IA32_AOUT
2330 tristate "IA32 a.out support"
2331 depends on IA32_EMULATION
2332 ---help---
2333 Support old a.out binaries in the 32bit emulation.
2334
2335 config X86_X32
2336 bool "x32 ABI for 64-bit mode"
2337 depends on X86_64 && IA32_EMULATION
2338 ---help---
2339 Include code to run binaries for the x32 native 32-bit ABI
2340 for 64-bit processors. An x32 process gets access to the
2341 full 64-bit register file and wide data path while leaving
2342 pointers at 32 bits for smaller memory footprint.
2343
2344 You will need a recent binutils (2.22 or later) with
2345 elf32_x86_64 support enabled to compile a kernel with this
2346 option set.
2347
2348 config COMPAT
2349 def_bool y
2350 depends on IA32_EMULATION || X86_X32
2351 select ARCH_WANT_OLD_COMPAT_IPC
2352
2353 if COMPAT
2354 config COMPAT_FOR_U64_ALIGNMENT
2355 def_bool y
2356
2357 config SYSVIPC_COMPAT
2358 def_bool y
2359 depends on SYSVIPC
2360
2361 config KEYS_COMPAT
2362 def_bool y
2363 depends on KEYS
2364 endif
2365
2366 endmenu
2367
2368
2369 config HAVE_ATOMIC_IOMAP
2370 def_bool y
2371 depends on X86_32
2372
2373 config X86_DEV_DMA_OPS
2374 bool
2375 depends on X86_64 || STA2X11
2376
2377 config X86_DMA_REMAP
2378 bool
2379 depends on STA2X11
2380
2381 source "net/Kconfig"
2382
2383 source "drivers/Kconfig"
2384
2385 source "drivers/firmware/Kconfig"
2386
2387 source "fs/Kconfig"
2388
2389 source "arch/x86/Kconfig.debug"
2390
2391 source "security/Kconfig"
2392
2393 source "crypto/Kconfig"
2394
2395 source "arch/x86/kvm/Kconfig"
2396
2397 source "lib/Kconfig"