Merge remote-tracking branches 'regulator/topic/lp8755', 'regulator/topic/ltc3589...
[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 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 ARCH_MIGHT_HAVE_PC_SERIO
27 select HAVE_AOUT if X86_32
28 select HAVE_UNSTABLE_SCHED_CLOCK
29 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
30 select ARCH_SUPPORTS_INT128 if X86_64
31 select ARCH_WANTS_PROT_NUMA_PROT_NONE
32 select HAVE_IDE
33 select HAVE_OPROFILE
34 select HAVE_PCSPKR_PLATFORM
35 select HAVE_PERF_EVENTS
36 select HAVE_IOREMAP_PROT
37 select HAVE_KPROBES
38 select HAVE_MEMBLOCK
39 select HAVE_MEMBLOCK_NODE_MAP
40 select ARCH_DISCARD_MEMBLOCK
41 select ARCH_WANT_OPTIONAL_GPIOLIB
42 select ARCH_WANT_FRAME_POINTERS
43 select HAVE_DMA_ATTRS
44 select HAVE_DMA_CONTIGUOUS
45 select HAVE_KRETPROBES
46 select GENERIC_EARLY_IOREMAP
47 select HAVE_OPTPROBES
48 select HAVE_KPROBES_ON_FTRACE
49 select HAVE_FTRACE_MCOUNT_RECORD
50 select HAVE_FENTRY if X86_64
51 select HAVE_C_RECORDMCOUNT
52 select HAVE_DYNAMIC_FTRACE
53 select HAVE_DYNAMIC_FTRACE_WITH_REGS
54 select HAVE_FUNCTION_TRACER
55 select HAVE_FUNCTION_GRAPH_TRACER
56 select HAVE_FUNCTION_GRAPH_FP_TEST
57 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
58 select HAVE_SYSCALL_TRACEPOINTS
59 select SYSCTL_EXCEPTION_TRACE
60 select HAVE_KVM
61 select HAVE_ARCH_KGDB
62 select HAVE_ARCH_TRACEHOOK
63 select HAVE_GENERIC_DMA_COHERENT if X86_32
64 select HAVE_EFFICIENT_UNALIGNED_ACCESS
65 select USER_STACKTRACE_SUPPORT
66 select HAVE_REGS_AND_STACK_ACCESS_API
67 select HAVE_DMA_API_DEBUG
68 select HAVE_KERNEL_GZIP
69 select HAVE_KERNEL_BZIP2
70 select HAVE_KERNEL_LZMA
71 select HAVE_KERNEL_XZ
72 select HAVE_KERNEL_LZO
73 select HAVE_KERNEL_LZ4
74 select HAVE_HW_BREAKPOINT
75 select HAVE_MIXED_BREAKPOINTS_REGS
76 select PERF_EVENTS
77 select HAVE_PERF_EVENTS_NMI
78 select HAVE_PERF_REGS
79 select HAVE_PERF_USER_STACK_DUMP
80 select HAVE_DEBUG_KMEMLEAK
81 select ANON_INODES
82 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
83 select HAVE_CMPXCHG_LOCAL
84 select HAVE_CMPXCHG_DOUBLE
85 select HAVE_ARCH_KMEMCHECK
86 select HAVE_USER_RETURN_NOTIFIER
87 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
88 select HAVE_ARCH_JUMP_LABEL
89 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90 select SPARSE_IRQ
91 select GENERIC_FIND_FIRST_BIT
92 select GENERIC_IRQ_PROBE
93 select GENERIC_PENDING_IRQ if SMP
94 select GENERIC_IRQ_SHOW
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select IRQ_FORCED_THREADING
97 select HAVE_BPF_JIT if X86_64
98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select CLKEVT_I8253
100 select ARCH_HAVE_NMI_SAFE_CMPXCHG
101 select GENERIC_IOMAP
102 select DCACHE_WORD_ACCESS
103 select GENERIC_SMP_IDLE_THREAD
104 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
105 select HAVE_ARCH_SECCOMP_FILTER
106 select BUILDTIME_EXTABLE_SORT
107 select GENERIC_CMOS_UPDATE
108 select HAVE_ARCH_SOFT_DIRTY if X86_64
109 select CLOCKSOURCE_WATCHDOG
110 select GENERIC_CLOCKEVENTS
111 select ARCH_CLOCKSOURCE_DATA
112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113 select GENERIC_TIME_VSYSCALL
114 select KTIME_SCALAR if X86_32
115 select GENERIC_STRNCPY_FROM_USER
116 select GENERIC_STRNLEN_USER
117 select HAVE_CONTEXT_TRACKING if X86_64
118 select HAVE_IRQ_TIME_ACCOUNTING
119 select VIRT_TO_BUS
120 select MODULES_USE_ELF_REL if X86_32
121 select MODULES_USE_ELF_RELA if X86_64
122 select CLONE_BACKWARDS if X86_32
123 select ARCH_USE_BUILTIN_BSWAP
124 select ARCH_USE_QUEUE_RWLOCK
125 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
126 select OLD_SIGACTION if X86_32
127 select COMPAT_OLD_SIGACTION if IA32_EMULATION
128 select RTC_LIB
129 select HAVE_DEBUG_STACKOVERFLOW
130 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
131 select HAVE_CC_STACKPROTECTOR
132 select GENERIC_CPU_AUTOPROBE
133 select HAVE_ARCH_AUDITSYSCALL
134 select ARCH_SUPPORTS_ATOMIC_RMW
135
136 config INSTRUCTION_DECODER
137 def_bool y
138 depends on KPROBES || PERF_EVENTS || UPROBES
139
140 config OUTPUT_FORMAT
141 string
142 default "elf32-i386" if X86_32
143 default "elf64-x86-64" if X86_64
144
145 config ARCH_DEFCONFIG
146 string
147 default "arch/x86/configs/i386_defconfig" if X86_32
148 default "arch/x86/configs/x86_64_defconfig" if X86_64
149
150 config LOCKDEP_SUPPORT
151 def_bool y
152
153 config STACKTRACE_SUPPORT
154 def_bool y
155
156 config HAVE_LATENCYTOP_SUPPORT
157 def_bool y
158
159 config MMU
160 def_bool y
161
162 config SBUS
163 bool
164
165 config NEED_DMA_MAP_STATE
166 def_bool y
167 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
168
169 config NEED_SG_DMA_LENGTH
170 def_bool y
171
172 config GENERIC_ISA_DMA
173 def_bool y
174 depends on ISA_DMA_API
175
176 config GENERIC_BUG
177 def_bool y
178 depends on BUG
179 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
180
181 config GENERIC_BUG_RELATIVE_POINTERS
182 bool
183
184 config GENERIC_HWEIGHT
185 def_bool y
186
187 config ARCH_MAY_HAVE_PC_FDC
188 def_bool y
189 depends on ISA_DMA_API
190
191 config RWSEM_XCHGADD_ALGORITHM
192 def_bool y
193
194 config GENERIC_CALIBRATE_DELAY
195 def_bool y
196
197 config ARCH_HAS_CPU_RELAX
198 def_bool y
199
200 config ARCH_HAS_CACHE_LINE_SIZE
201 def_bool y
202
203 config HAVE_SETUP_PER_CPU_AREA
204 def_bool y
205
206 config NEED_PER_CPU_EMBED_FIRST_CHUNK
207 def_bool y
208
209 config NEED_PER_CPU_PAGE_FIRST_CHUNK
210 def_bool y
211
212 config ARCH_HIBERNATION_POSSIBLE
213 def_bool y
214
215 config ARCH_SUSPEND_POSSIBLE
216 def_bool y
217
218 config ARCH_WANT_HUGE_PMD_SHARE
219 def_bool y
220
221 config ARCH_WANT_GENERAL_HUGETLB
222 def_bool y
223
224 config ZONE_DMA32
225 bool
226 default X86_64
227
228 config AUDIT_ARCH
229 bool
230 default X86_64
231
232 config ARCH_SUPPORTS_OPTIMIZED_INLINING
233 def_bool y
234
235 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
236 def_bool y
237
238 config HAVE_INTEL_TXT
239 def_bool y
240 depends on INTEL_IOMMU && ACPI
241
242 config X86_32_SMP
243 def_bool y
244 depends on X86_32 && SMP
245
246 config X86_64_SMP
247 def_bool y
248 depends on X86_64 && SMP
249
250 config X86_HT
251 def_bool y
252 depends on SMP
253
254 config X86_32_LAZY_GS
255 def_bool y
256 depends on X86_32 && !CC_STACKPROTECTOR
257
258 config ARCH_HWEIGHT_CFLAGS
259 string
260 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
261 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
262
263 config ARCH_SUPPORTS_UPROBES
264 def_bool y
265
266 config FIX_EARLYCON_MEM
267 def_bool y
268
269 source "init/Kconfig"
270 source "kernel/Kconfig.freezer"
271
272 menu "Processor type and features"
273
274 config ZONE_DMA
275 bool "DMA memory allocation support" if EXPERT
276 default y
277 help
278 DMA memory allocation support allows devices with less than 32-bit
279 addressing to allocate within the first 16MB of address space.
280 Disable if no such devices will be used.
281
282 If unsure, say Y.
283
284 config SMP
285 bool "Symmetric multi-processing support"
286 ---help---
287 This enables support for systems with more than one CPU. If you have
288 a system with only one CPU, say N. If you have a system with more
289 than one CPU, say Y.
290
291 If you say N here, the kernel will run on uni- and multiprocessor
292 machines, but will use only one CPU of a multiprocessor machine. If
293 you say Y here, the kernel will run on many, but not all,
294 uniprocessor machines. On a uniprocessor machine, the kernel
295 will run faster if you say N here.
296
297 Note that if you say Y here and choose architecture "586" or
298 "Pentium" under "Processor family", the kernel will not work on 486
299 architectures. Similarly, multiprocessor kernels for the "PPro"
300 architecture may not work on all Pentium based boards.
301
302 People using multiprocessor machines who say Y here should also say
303 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
304 Management" code will be disabled if you say Y here.
305
306 See also <file:Documentation/x86/i386/IO-APIC.txt>,
307 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
308 <http://www.tldp.org/docs.html#howto>.
309
310 If you don't know what to do here, say N.
311
312 config X86_X2APIC
313 bool "Support x2apic"
314 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
315 ---help---
316 This enables x2apic support on CPUs that have this feature.
317
318 This allows 32-bit apic IDs (so it can support very large systems),
319 and accesses the local apic via MSRs not via mmio.
320
321 If you don't know what to do here, say N.
322
323 config X86_MPPARSE
324 bool "Enable MPS table" if ACPI || SFI
325 default y
326 depends on X86_LOCAL_APIC
327 ---help---
328 For old smp systems that do not have proper acpi support. Newer systems
329 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
330
331 config X86_BIGSMP
332 bool "Support for big SMP systems with more than 8 CPUs"
333 depends on X86_32 && SMP
334 ---help---
335 This option is needed for the systems that have more than 8 CPUs
336
337 config GOLDFISH
338 def_bool y
339 depends on X86_GOLDFISH
340
341 if X86_32
342 config X86_EXTENDED_PLATFORM
343 bool "Support for extended (non-PC) x86 platforms"
344 default y
345 ---help---
346 If you disable this option then the kernel will only support
347 standard PC platforms. (which covers the vast majority of
348 systems out there.)
349
350 If you enable this option then you'll be able to select support
351 for the following (non-PC) 32 bit x86 platforms:
352 Goldfish (Android emulator)
353 AMD Elan
354 RDC R-321x SoC
355 SGI 320/540 (Visual Workstation)
356 STA2X11-based (e.g. Northville)
357 Moorestown MID devices
358
359 If you have one of these systems, or if you want to build a
360 generic distribution kernel, say Y here - otherwise say N.
361 endif
362
363 if X86_64
364 config X86_EXTENDED_PLATFORM
365 bool "Support for extended (non-PC) x86 platforms"
366 default y
367 ---help---
368 If you disable this option then the kernel will only support
369 standard PC platforms. (which covers the vast majority of
370 systems out there.)
371
372 If you enable this option then you'll be able to select support
373 for the following (non-PC) 64 bit x86 platforms:
374 Numascale NumaChip
375 ScaleMP vSMP
376 SGI Ultraviolet
377
378 If you have one of these systems, or if you want to build a
379 generic distribution kernel, say Y here - otherwise say N.
380 endif
381 # This is an alphabetically sorted list of 64 bit extended platforms
382 # Please maintain the alphabetic order if and when there are additions
383 config X86_NUMACHIP
384 bool "Numascale NumaChip"
385 depends on X86_64
386 depends on X86_EXTENDED_PLATFORM
387 depends on NUMA
388 depends on SMP
389 depends on X86_X2APIC
390 depends on PCI_MMCONFIG
391 ---help---
392 Adds support for Numascale NumaChip large-SMP systems. Needed to
393 enable more than ~168 cores.
394 If you don't have one of these, you should say N here.
395
396 config X86_VSMP
397 bool "ScaleMP vSMP"
398 select HYPERVISOR_GUEST
399 select PARAVIRT
400 depends on X86_64 && PCI
401 depends on X86_EXTENDED_PLATFORM
402 depends on SMP
403 ---help---
404 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
405 supposed to run on these EM64T-based machines. Only choose this option
406 if you have one of these machines.
407
408 config X86_UV
409 bool "SGI Ultraviolet"
410 depends on X86_64
411 depends on X86_EXTENDED_PLATFORM
412 depends on NUMA
413 depends on X86_X2APIC
414 ---help---
415 This option is needed in order to support SGI Ultraviolet systems.
416 If you don't have one of these, you should say N here.
417
418 # Following is an alphabetically sorted list of 32 bit extended platforms
419 # Please maintain the alphabetic order if and when there are additions
420
421 config X86_GOLDFISH
422 bool "Goldfish (Virtual Platform)"
423 depends on X86_EXTENDED_PLATFORM
424 ---help---
425 Enable support for the Goldfish virtual platform used primarily
426 for Android development. Unless you are building for the Android
427 Goldfish emulator say N here.
428
429 config X86_INTEL_CE
430 bool "CE4100 TV platform"
431 depends on PCI
432 depends on PCI_GODIRECT
433 depends on X86_32
434 depends on X86_EXTENDED_PLATFORM
435 select X86_REBOOTFIXUPS
436 select OF
437 select OF_EARLY_FLATTREE
438 select IRQ_DOMAIN
439 ---help---
440 Select for the Intel CE media processor (CE4100) SOC.
441 This option compiles in support for the CE4100 SOC for settop
442 boxes and media devices.
443
444 config X86_INTEL_MID
445 bool "Intel MID platform support"
446 depends on X86_32
447 depends on X86_EXTENDED_PLATFORM
448 depends on X86_PLATFORM_DEVICES
449 depends on PCI
450 depends on PCI_GOANY
451 depends on X86_IO_APIC
452 select SFI
453 select I2C
454 select DW_APB_TIMER
455 select APB_TIMER
456 select INTEL_SCU_IPC
457 select MFD_INTEL_MSIC
458 ---help---
459 Select to build a kernel capable of supporting Intel MID (Mobile
460 Internet Device) platform systems which do not have the PCI legacy
461 interfaces. If you are building for a PC class system say N here.
462
463 Intel MID platforms are based on an Intel processor and chipset which
464 consume less power than most of the x86 derivatives.
465
466 config X86_INTEL_LPSS
467 bool "Intel Low Power Subsystem Support"
468 depends on ACPI
469 select COMMON_CLK
470 select PINCTRL
471 ---help---
472 Select to build support for Intel Low Power Subsystem such as
473 found on Intel Lynxpoint PCH. Selecting this option enables
474 things like clock tree (common clock framework) and pincontrol
475 which are needed by the LPSS peripheral drivers.
476
477 config X86_RDC321X
478 bool "RDC R-321x SoC"
479 depends on X86_32
480 depends on X86_EXTENDED_PLATFORM
481 select M486
482 select X86_REBOOTFIXUPS
483 ---help---
484 This option is needed for RDC R-321x system-on-chip, also known
485 as R-8610-(G).
486 If you don't have one of these chips, you should say N here.
487
488 config X86_32_NON_STANDARD
489 bool "Support non-standard 32-bit SMP architectures"
490 depends on X86_32 && SMP
491 depends on X86_EXTENDED_PLATFORM
492 ---help---
493 This option compiles in the bigsmp and STA2X11 default
494 subarchitectures. It is intended for a generic binary
495 kernel. If you select them all, kernel will probe it one by
496 one and will fallback to default.
497
498 # Alphabetically sorted list of Non standard 32 bit platforms
499
500 config X86_SUPPORTS_MEMORY_FAILURE
501 def_bool y
502 # MCE code calls memory_failure():
503 depends on X86_MCE
504 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
505 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
506 depends on X86_64 || !SPARSEMEM
507 select ARCH_SUPPORTS_MEMORY_FAILURE
508
509 config STA2X11
510 bool "STA2X11 Companion Chip Support"
511 depends on X86_32_NON_STANDARD && PCI
512 select X86_DEV_DMA_OPS
513 select X86_DMA_REMAP
514 select SWIOTLB
515 select MFD_STA2X11
516 select ARCH_REQUIRE_GPIOLIB
517 default n
518 ---help---
519 This adds support for boards based on the STA2X11 IO-Hub,
520 a.k.a. "ConneXt". The chip is used in place of the standard
521 PC chipset, so all "standard" peripherals are missing. If this
522 option is selected the kernel will still be able to boot on
523 standard PC machines.
524
525 config X86_32_IRIS
526 tristate "Eurobraille/Iris poweroff module"
527 depends on X86_32
528 ---help---
529 The Iris machines from EuroBraille do not have APM or ACPI support
530 to shut themselves down properly. A special I/O sequence is
531 needed to do so, which is what this module does at
532 kernel shutdown.
533
534 This is only for Iris machines from EuroBraille.
535
536 If unused, say N.
537
538 config SCHED_OMIT_FRAME_POINTER
539 def_bool y
540 prompt "Single-depth WCHAN output"
541 depends on X86
542 ---help---
543 Calculate simpler /proc/<PID>/wchan values. If this option
544 is disabled then wchan values will recurse back to the
545 caller function. This provides more accurate wchan values,
546 at the expense of slightly more scheduling overhead.
547
548 If in doubt, say "Y".
549
550 menuconfig HYPERVISOR_GUEST
551 bool "Linux guest support"
552 ---help---
553 Say Y here to enable options for running Linux under various hyper-
554 visors. This option enables basic hypervisor detection and platform
555 setup.
556
557 If you say N, all options in this submenu will be skipped and
558 disabled, and Linux guest support won't be built in.
559
560 if HYPERVISOR_GUEST
561
562 config PARAVIRT
563 bool "Enable paravirtualization code"
564 ---help---
565 This changes the kernel so it can modify itself when it is run
566 under a hypervisor, potentially improving performance significantly
567 over full virtualization. However, when run without a hypervisor
568 the kernel is theoretically slower and slightly larger.
569
570 config PARAVIRT_DEBUG
571 bool "paravirt-ops debugging"
572 depends on PARAVIRT && DEBUG_KERNEL
573 ---help---
574 Enable to debug paravirt_ops internals. Specifically, BUG if
575 a paravirt_op is missing when it is called.
576
577 config PARAVIRT_SPINLOCKS
578 bool "Paravirtualization layer for spinlocks"
579 depends on PARAVIRT && SMP
580 select UNINLINE_SPIN_UNLOCK
581 ---help---
582 Paravirtualized spinlocks allow a pvops backend to replace the
583 spinlock implementation with something virtualization-friendly
584 (for example, block the virtual CPU rather than spinning).
585
586 It has a minimal impact on native kernels and gives a nice performance
587 benefit on paravirtualized KVM / Xen kernels.
588
589 If you are unsure how to answer this question, answer Y.
590
591 source "arch/x86/xen/Kconfig"
592
593 config KVM_GUEST
594 bool "KVM Guest support (including kvmclock)"
595 depends on PARAVIRT
596 select PARAVIRT_CLOCK
597 default y
598 ---help---
599 This option enables various optimizations for running under the KVM
600 hypervisor. It includes a paravirtualized clock, so that instead
601 of relying on a PIT (or probably other) emulation by the
602 underlying device model, the host provides the guest with
603 timing infrastructure such as time of day, and system time
604
605 config KVM_DEBUG_FS
606 bool "Enable debug information for KVM Guests in debugfs"
607 depends on KVM_GUEST && DEBUG_FS
608 default n
609 ---help---
610 This option enables collection of various statistics for KVM guest.
611 Statistics are displayed in debugfs filesystem. Enabling this option
612 may incur significant overhead.
613
614 source "arch/x86/lguest/Kconfig"
615
616 config PARAVIRT_TIME_ACCOUNTING
617 bool "Paravirtual steal time accounting"
618 depends on PARAVIRT
619 default n
620 ---help---
621 Select this option to enable fine granularity task steal time
622 accounting. Time spent executing other tasks in parallel with
623 the current vCPU is discounted from the vCPU power. To account for
624 that, there can be a small performance impact.
625
626 If in doubt, say N here.
627
628 config PARAVIRT_CLOCK
629 bool
630
631 endif #HYPERVISOR_GUEST
632
633 config NO_BOOTMEM
634 def_bool y
635
636 config MEMTEST
637 bool "Memtest"
638 ---help---
639 This option adds a kernel parameter 'memtest', which allows memtest
640 to be set.
641 memtest=0, mean disabled; -- default
642 memtest=1, mean do 1 test pattern;
643 ...
644 memtest=4, mean do 4 test patterns.
645 If you are unsure how to answer this question, answer N.
646
647 source "arch/x86/Kconfig.cpu"
648
649 config HPET_TIMER
650 def_bool X86_64
651 prompt "HPET Timer Support" if X86_32
652 ---help---
653 Use the IA-PC HPET (High Precision Event Timer) to manage
654 time in preference to the PIT and RTC, if a HPET is
655 present.
656 HPET is the next generation timer replacing legacy 8254s.
657 The HPET provides a stable time base on SMP
658 systems, unlike the TSC, but it is more expensive to access,
659 as it is off-chip. You can find the HPET spec at
660 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
661
662 You can safely choose Y here. However, HPET will only be
663 activated if the platform and the BIOS support this feature.
664 Otherwise the 8254 will be used for timing services.
665
666 Choose N to continue using the legacy 8254 timer.
667
668 config HPET_EMULATE_RTC
669 def_bool y
670 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
671
672 config APB_TIMER
673 def_bool y if X86_INTEL_MID
674 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
675 select DW_APB_TIMER
676 depends on X86_INTEL_MID && SFI
677 help
678 APB timer is the replacement for 8254, HPET on X86 MID platforms.
679 The APBT provides a stable time base on SMP
680 systems, unlike the TSC, but it is more expensive to access,
681 as it is off-chip. APB timers are always running regardless of CPU
682 C states, they are used as per CPU clockevent device when possible.
683
684 # Mark as expert because too many people got it wrong.
685 # The code disables itself when not needed.
686 config DMI
687 default y
688 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
689 bool "Enable DMI scanning" if EXPERT
690 ---help---
691 Enabled scanning of DMI to identify machine quirks. Say Y
692 here unless you have verified that your setup is not
693 affected by entries in the DMI blacklist. Required by PNP
694 BIOS code.
695
696 config GART_IOMMU
697 bool "Old AMD GART IOMMU support"
698 select SWIOTLB
699 depends on X86_64 && PCI && AMD_NB
700 ---help---
701 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
702 GART based hardware IOMMUs.
703
704 The GART supports full DMA access for devices with 32-bit access
705 limitations, on systems with more than 3 GB. This is usually needed
706 for USB, sound, many IDE/SATA chipsets and some other devices.
707
708 Newer systems typically have a modern AMD IOMMU, supported via
709 the CONFIG_AMD_IOMMU=y config option.
710
711 In normal configurations this driver is only active when needed:
712 there's more than 3 GB of memory and the system contains a
713 32-bit limited device.
714
715 If unsure, say Y.
716
717 config CALGARY_IOMMU
718 bool "IBM Calgary IOMMU support"
719 select SWIOTLB
720 depends on X86_64 && PCI
721 ---help---
722 Support for hardware IOMMUs in IBM's xSeries x366 and x460
723 systems. Needed to run systems with more than 3GB of memory
724 properly with 32-bit PCI devices that do not support DAC
725 (Double Address Cycle). Calgary also supports bus level
726 isolation, where all DMAs pass through the IOMMU. This
727 prevents them from going anywhere except their intended
728 destination. This catches hard-to-find kernel bugs and
729 mis-behaving drivers and devices that do not use the DMA-API
730 properly to set up their DMA buffers. The IOMMU can be
731 turned off at boot time with the iommu=off parameter.
732 Normally the kernel will make the right choice by itself.
733 If unsure, say Y.
734
735 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
736 def_bool y
737 prompt "Should Calgary be enabled by default?"
738 depends on CALGARY_IOMMU
739 ---help---
740 Should Calgary be enabled by default? if you choose 'y', Calgary
741 will be used (if it exists). If you choose 'n', Calgary will not be
742 used even if it exists. If you choose 'n' and would like to use
743 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
744 If unsure, say Y.
745
746 # need this always selected by IOMMU for the VIA workaround
747 config SWIOTLB
748 def_bool y if X86_64
749 ---help---
750 Support for software bounce buffers used on x86-64 systems
751 which don't have a hardware IOMMU. Using this PCI devices
752 which can only access 32-bits of memory can be used on systems
753 with more than 3 GB of memory.
754 If unsure, say Y.
755
756 config IOMMU_HELPER
757 def_bool y
758 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
759
760 config MAXSMP
761 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
762 depends on X86_64 && SMP && DEBUG_KERNEL
763 select CPUMASK_OFFSTACK
764 ---help---
765 Enable maximum number of CPUS and NUMA Nodes for this architecture.
766 If unsure, say N.
767
768 config NR_CPUS
769 int "Maximum number of CPUs" if SMP && !MAXSMP
770 range 2 8 if SMP && X86_32 && !X86_BIGSMP
771 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
772 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
773 default "1" if !SMP
774 default "8192" if MAXSMP
775 default "32" if SMP && X86_BIGSMP
776 default "8" if SMP
777 ---help---
778 This allows you to specify the maximum number of CPUs which this
779 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
780 supported value is 4096, otherwise the maximum value is 512. The
781 minimum value which makes sense is 2.
782
783 This is purely to save memory - each supported CPU adds
784 approximately eight kilobytes to the kernel image.
785
786 config SCHED_SMT
787 bool "SMT (Hyperthreading) scheduler support"
788 depends on X86_HT
789 ---help---
790 SMT scheduler support improves the CPU scheduler's decision making
791 when dealing with Intel Pentium 4 chips with HyperThreading at a
792 cost of slightly increased overhead in some places. If unsure say
793 N here.
794
795 config SCHED_MC
796 def_bool y
797 prompt "Multi-core scheduler support"
798 depends on X86_HT
799 ---help---
800 Multi-core scheduler support improves the CPU scheduler's decision
801 making when dealing with multi-core CPU chips at a cost of slightly
802 increased overhead in some places. If unsure say N here.
803
804 source "kernel/Kconfig.preempt"
805
806 config X86_UP_APIC
807 bool "Local APIC support on uniprocessors"
808 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
809 ---help---
810 A local APIC (Advanced Programmable Interrupt Controller) is an
811 integrated interrupt controller in the CPU. If you have a single-CPU
812 system which has a processor with a local APIC, you can say Y here to
813 enable and use it. If you say Y here even though your machine doesn't
814 have a local APIC, then the kernel will still run with no slowdown at
815 all. The local APIC supports CPU-generated self-interrupts (timer,
816 performance counters), and the NMI watchdog which detects hard
817 lockups.
818
819 config X86_UP_IOAPIC
820 bool "IO-APIC support on uniprocessors"
821 depends on X86_UP_APIC
822 ---help---
823 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
824 SMP-capable replacement for PC-style interrupt controllers. Most
825 SMP systems and many recent uniprocessor systems have one.
826
827 If you have a single-CPU system with an IO-APIC, you can say Y here
828 to use it. If you say Y here even though your machine doesn't have
829 an IO-APIC, then the kernel will still run with no slowdown at all.
830
831 config X86_LOCAL_APIC
832 def_bool y
833 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
834
835 config X86_IO_APIC
836 def_bool y
837 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
838 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
839
840 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
841 bool "Reroute for broken boot IRQs"
842 depends on X86_IO_APIC
843 ---help---
844 This option enables a workaround that fixes a source of
845 spurious interrupts. This is recommended when threaded
846 interrupt handling is used on systems where the generation of
847 superfluous "boot interrupts" cannot be disabled.
848
849 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
850 entry in the chipset's IO-APIC is masked (as, e.g. the RT
851 kernel does during interrupt handling). On chipsets where this
852 boot IRQ generation cannot be disabled, this workaround keeps
853 the original IRQ line masked so that only the equivalent "boot
854 IRQ" is delivered to the CPUs. The workaround also tells the
855 kernel to set up the IRQ handler on the boot IRQ line. In this
856 way only one interrupt is delivered to the kernel. Otherwise
857 the spurious second interrupt may cause the kernel to bring
858 down (vital) interrupt lines.
859
860 Only affects "broken" chipsets. Interrupt sharing may be
861 increased on these systems.
862
863 config X86_MCE
864 bool "Machine Check / overheating reporting"
865 default y
866 ---help---
867 Machine Check support allows the processor to notify the
868 kernel if it detects a problem (e.g. overheating, data corruption).
869 The action the kernel takes depends on the severity of the problem,
870 ranging from warning messages to halting the machine.
871
872 config X86_MCE_INTEL
873 def_bool y
874 prompt "Intel MCE features"
875 depends on X86_MCE && X86_LOCAL_APIC
876 ---help---
877 Additional support for intel specific MCE features such as
878 the thermal monitor.
879
880 config X86_MCE_AMD
881 def_bool y
882 prompt "AMD MCE features"
883 depends on X86_MCE && X86_LOCAL_APIC
884 ---help---
885 Additional support for AMD specific MCE features such as
886 the DRAM Error Threshold.
887
888 config X86_ANCIENT_MCE
889 bool "Support for old Pentium 5 / WinChip machine checks"
890 depends on X86_32 && X86_MCE
891 ---help---
892 Include support for machine check handling on old Pentium 5 or WinChip
893 systems. These typically need to be enabled explicitly on the command
894 line.
895
896 config X86_MCE_THRESHOLD
897 depends on X86_MCE_AMD || X86_MCE_INTEL
898 def_bool y
899
900 config X86_MCE_INJECT
901 depends on X86_MCE
902 tristate "Machine check injector support"
903 ---help---
904 Provide support for injecting machine checks for testing purposes.
905 If you don't know what a machine check is and you don't do kernel
906 QA it is safe to say n.
907
908 config X86_THERMAL_VECTOR
909 def_bool y
910 depends on X86_MCE_INTEL
911
912 config VM86
913 bool "Enable VM86 support" if EXPERT
914 default y
915 depends on X86_32
916 ---help---
917 This option is required by programs like DOSEMU to run
918 16-bit real mode legacy code on x86 processors. It also may
919 be needed by software like XFree86 to initialize some video
920 cards via BIOS. Disabling this option saves about 6K.
921
922 config X86_16BIT
923 bool "Enable support for 16-bit segments" if EXPERT
924 default y
925 ---help---
926 This option is required by programs like Wine to run 16-bit
927 protected mode legacy code on x86 processors. Disabling
928 this option saves about 300 bytes on i386, or around 6K text
929 plus 16K runtime memory on x86-64,
930
931 config X86_ESPFIX32
932 def_bool y
933 depends on X86_16BIT && X86_32
934
935 config X86_ESPFIX64
936 def_bool y
937 depends on X86_16BIT && X86_64
938
939 config TOSHIBA
940 tristate "Toshiba Laptop support"
941 depends on X86_32
942 ---help---
943 This adds a driver to safely access the System Management Mode of
944 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
945 not work on models with a Phoenix BIOS. The System Management Mode
946 is used to set the BIOS and power saving options on Toshiba portables.
947
948 For information on utilities to make use of this driver see the
949 Toshiba Linux utilities web site at:
950 <http://www.buzzard.org.uk/toshiba/>.
951
952 Say Y if you intend to run this kernel on a Toshiba portable.
953 Say N otherwise.
954
955 config I8K
956 tristate "Dell laptop support"
957 select HWMON
958 ---help---
959 This adds a driver to safely access the System Management Mode
960 of the CPU on the Dell Inspiron 8000. The System Management Mode
961 is used to read cpu temperature and cooling fan status and to
962 control the fans on the I8K portables.
963
964 This driver has been tested only on the Inspiron 8000 but it may
965 also work with other Dell laptops. You can force loading on other
966 models by passing the parameter `force=1' to the module. Use at
967 your own risk.
968
969 For information on utilities to make use of this driver see the
970 I8K Linux utilities web site at:
971 <http://people.debian.org/~dz/i8k/>
972
973 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
974 Say N otherwise.
975
976 config X86_REBOOTFIXUPS
977 bool "Enable X86 board specific fixups for reboot"
978 depends on X86_32
979 ---help---
980 This enables chipset and/or board specific fixups to be done
981 in order to get reboot to work correctly. This is only needed on
982 some combinations of hardware and BIOS. The symptom, for which
983 this config is intended, is when reboot ends with a stalled/hung
984 system.
985
986 Currently, the only fixup is for the Geode machines using
987 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
988
989 Say Y if you want to enable the fixup. Currently, it's safe to
990 enable this option even if you don't need it.
991 Say N otherwise.
992
993 config MICROCODE
994 tristate "CPU microcode loading support"
995 depends on CPU_SUP_AMD || CPU_SUP_INTEL
996 select FW_LOADER
997 ---help---
998
999 If you say Y here, you will be able to update the microcode on
1000 certain Intel and AMD processors. The Intel support is for the
1001 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1002 Xeon etc. The AMD support is for families 0x10 and later. You will
1003 obviously need the actual microcode binary data itself which is not
1004 shipped with the Linux kernel.
1005
1006 This option selects the general module only, you need to select
1007 at least one vendor specific module as well.
1008
1009 To compile this driver as a module, choose M here: the module
1010 will be called microcode.
1011
1012 config MICROCODE_INTEL
1013 bool "Intel microcode loading support"
1014 depends on MICROCODE
1015 default MICROCODE
1016 select FW_LOADER
1017 ---help---
1018 This options enables microcode patch loading support for Intel
1019 processors.
1020
1021 For the current Intel microcode data package go to
1022 <https://downloadcenter.intel.com> and search for
1023 'Linux Processor Microcode Data File'.
1024
1025 config MICROCODE_AMD
1026 bool "AMD microcode loading support"
1027 depends on MICROCODE
1028 select FW_LOADER
1029 ---help---
1030 If you select this option, microcode patch loading support for AMD
1031 processors will be enabled.
1032
1033 config MICROCODE_OLD_INTERFACE
1034 def_bool y
1035 depends on MICROCODE
1036
1037 config MICROCODE_INTEL_EARLY
1038 def_bool n
1039
1040 config MICROCODE_AMD_EARLY
1041 def_bool n
1042
1043 config MICROCODE_EARLY
1044 bool "Early load microcode"
1045 depends on MICROCODE=y && BLK_DEV_INITRD
1046 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1047 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1048 default y
1049 help
1050 This option provides functionality to read additional microcode data
1051 at the beginning of initrd image. The data tells kernel to load
1052 microcode to CPU's as early as possible. No functional change if no
1053 microcode data is glued to the initrd, therefore it's safe to say Y.
1054
1055 config X86_MSR
1056 tristate "/dev/cpu/*/msr - Model-specific register support"
1057 ---help---
1058 This device gives privileged processes access to the x86
1059 Model-Specific Registers (MSRs). It is a character device with
1060 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1061 MSR accesses are directed to a specific CPU on multi-processor
1062 systems.
1063
1064 config X86_CPUID
1065 tristate "/dev/cpu/*/cpuid - CPU information support"
1066 ---help---
1067 This device gives processes access to the x86 CPUID instruction to
1068 be executed on a specific processor. It is a character device
1069 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1070 /dev/cpu/31/cpuid.
1071
1072 choice
1073 prompt "High Memory Support"
1074 default HIGHMEM4G
1075 depends on X86_32
1076
1077 config NOHIGHMEM
1078 bool "off"
1079 ---help---
1080 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1081 However, the address space of 32-bit x86 processors is only 4
1082 Gigabytes large. That means that, if you have a large amount of
1083 physical memory, not all of it can be "permanently mapped" by the
1084 kernel. The physical memory that's not permanently mapped is called
1085 "high memory".
1086
1087 If you are compiling a kernel which will never run on a machine with
1088 more than 1 Gigabyte total physical RAM, answer "off" here (default
1089 choice and suitable for most users). This will result in a "3GB/1GB"
1090 split: 3GB are mapped so that each process sees a 3GB virtual memory
1091 space and the remaining part of the 4GB virtual memory space is used
1092 by the kernel to permanently map as much physical memory as
1093 possible.
1094
1095 If the machine has between 1 and 4 Gigabytes physical RAM, then
1096 answer "4GB" here.
1097
1098 If more than 4 Gigabytes is used then answer "64GB" here. This
1099 selection turns Intel PAE (Physical Address Extension) mode on.
1100 PAE implements 3-level paging on IA32 processors. PAE is fully
1101 supported by Linux, PAE mode is implemented on all recent Intel
1102 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1103 then the kernel will not boot on CPUs that don't support PAE!
1104
1105 The actual amount of total physical memory will either be
1106 auto detected or can be forced by using a kernel command line option
1107 such as "mem=256M". (Try "man bootparam" or see the documentation of
1108 your boot loader (lilo or loadlin) about how to pass options to the
1109 kernel at boot time.)
1110
1111 If unsure, say "off".
1112
1113 config HIGHMEM4G
1114 bool "4GB"
1115 ---help---
1116 Select this if you have a 32-bit processor and between 1 and 4
1117 gigabytes of physical RAM.
1118
1119 config HIGHMEM64G
1120 bool "64GB"
1121 depends on !M486
1122 select X86_PAE
1123 ---help---
1124 Select this if you have a 32-bit processor and more than 4
1125 gigabytes of physical RAM.
1126
1127 endchoice
1128
1129 choice
1130 prompt "Memory split" if EXPERT
1131 default VMSPLIT_3G
1132 depends on X86_32
1133 ---help---
1134 Select the desired split between kernel and user memory.
1135
1136 If the address range available to the kernel is less than the
1137 physical memory installed, the remaining memory will be available
1138 as "high memory". Accessing high memory is a little more costly
1139 than low memory, as it needs to be mapped into the kernel first.
1140 Note that increasing the kernel address space limits the range
1141 available to user programs, making the address space there
1142 tighter. Selecting anything other than the default 3G/1G split
1143 will also likely make your kernel incompatible with binary-only
1144 kernel modules.
1145
1146 If you are not absolutely sure what you are doing, leave this
1147 option alone!
1148
1149 config VMSPLIT_3G
1150 bool "3G/1G user/kernel split"
1151 config VMSPLIT_3G_OPT
1152 depends on !X86_PAE
1153 bool "3G/1G user/kernel split (for full 1G low memory)"
1154 config VMSPLIT_2G
1155 bool "2G/2G user/kernel split"
1156 config VMSPLIT_2G_OPT
1157 depends on !X86_PAE
1158 bool "2G/2G user/kernel split (for full 2G low memory)"
1159 config VMSPLIT_1G
1160 bool "1G/3G user/kernel split"
1161 endchoice
1162
1163 config PAGE_OFFSET
1164 hex
1165 default 0xB0000000 if VMSPLIT_3G_OPT
1166 default 0x80000000 if VMSPLIT_2G
1167 default 0x78000000 if VMSPLIT_2G_OPT
1168 default 0x40000000 if VMSPLIT_1G
1169 default 0xC0000000
1170 depends on X86_32
1171
1172 config HIGHMEM
1173 def_bool y
1174 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1175
1176 config X86_PAE
1177 bool "PAE (Physical Address Extension) Support"
1178 depends on X86_32 && !HIGHMEM4G
1179 ---help---
1180 PAE is required for NX support, and furthermore enables
1181 larger swapspace support for non-overcommit purposes. It
1182 has the cost of more pagetable lookup overhead, and also
1183 consumes more pagetable space per process.
1184
1185 config ARCH_PHYS_ADDR_T_64BIT
1186 def_bool y
1187 depends on X86_64 || X86_PAE
1188
1189 config ARCH_DMA_ADDR_T_64BIT
1190 def_bool y
1191 depends on X86_64 || HIGHMEM64G
1192
1193 config DIRECT_GBPAGES
1194 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1195 default y
1196 depends on X86_64
1197 ---help---
1198 Allow the kernel linear mapping to use 1GB pages on CPUs that
1199 support it. This can improve the kernel's performance a tiny bit by
1200 reducing TLB pressure. If in doubt, say "Y".
1201
1202 # Common NUMA Features
1203 config NUMA
1204 bool "Numa Memory Allocation and Scheduler Support"
1205 depends on SMP
1206 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1207 default y if X86_BIGSMP
1208 ---help---
1209 Enable NUMA (Non Uniform Memory Access) support.
1210
1211 The kernel will try to allocate memory used by a CPU on the
1212 local memory controller of the CPU and add some more
1213 NUMA awareness to the kernel.
1214
1215 For 64-bit this is recommended if the system is Intel Core i7
1216 (or later), AMD Opteron, or EM64T NUMA.
1217
1218 For 32-bit this is only needed if you boot a 32-bit
1219 kernel on a 64-bit NUMA platform.
1220
1221 Otherwise, you should say N.
1222
1223 config AMD_NUMA
1224 def_bool y
1225 prompt "Old style AMD Opteron NUMA detection"
1226 depends on X86_64 && NUMA && PCI
1227 ---help---
1228 Enable AMD NUMA node topology detection. You should say Y here if
1229 you have a multi processor AMD system. This uses an old method to
1230 read the NUMA configuration directly from the builtin Northbridge
1231 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1232 which also takes priority if both are compiled in.
1233
1234 config X86_64_ACPI_NUMA
1235 def_bool y
1236 prompt "ACPI NUMA detection"
1237 depends on X86_64 && NUMA && ACPI && PCI
1238 select ACPI_NUMA
1239 ---help---
1240 Enable ACPI SRAT based node topology detection.
1241
1242 # Some NUMA nodes have memory ranges that span
1243 # other nodes. Even though a pfn is valid and
1244 # between a node's start and end pfns, it may not
1245 # reside on that node. See memmap_init_zone()
1246 # for details.
1247 config NODES_SPAN_OTHER_NODES
1248 def_bool y
1249 depends on X86_64_ACPI_NUMA
1250
1251 config NUMA_EMU
1252 bool "NUMA emulation"
1253 depends on NUMA
1254 ---help---
1255 Enable NUMA emulation. A flat machine will be split
1256 into virtual nodes when booted with "numa=fake=N", where N is the
1257 number of nodes. This is only useful for debugging.
1258
1259 config NODES_SHIFT
1260 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1261 range 1 10
1262 default "10" if MAXSMP
1263 default "6" if X86_64
1264 default "3"
1265 depends on NEED_MULTIPLE_NODES
1266 ---help---
1267 Specify the maximum number of NUMA Nodes available on the target
1268 system. Increases memory reserved to accommodate various tables.
1269
1270 config ARCH_HAVE_MEMORY_PRESENT
1271 def_bool y
1272 depends on X86_32 && DISCONTIGMEM
1273
1274 config NEED_NODE_MEMMAP_SIZE
1275 def_bool y
1276 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1277
1278 config ARCH_FLATMEM_ENABLE
1279 def_bool y
1280 depends on X86_32 && !NUMA
1281
1282 config ARCH_DISCONTIGMEM_ENABLE
1283 def_bool y
1284 depends on NUMA && X86_32
1285
1286 config ARCH_DISCONTIGMEM_DEFAULT
1287 def_bool y
1288 depends on NUMA && X86_32
1289
1290 config ARCH_SPARSEMEM_ENABLE
1291 def_bool y
1292 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1293 select SPARSEMEM_STATIC if X86_32
1294 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1295
1296 config ARCH_SPARSEMEM_DEFAULT
1297 def_bool y
1298 depends on X86_64
1299
1300 config ARCH_SELECT_MEMORY_MODEL
1301 def_bool y
1302 depends on ARCH_SPARSEMEM_ENABLE
1303
1304 config ARCH_MEMORY_PROBE
1305 bool "Enable sysfs memory/probe interface"
1306 depends on X86_64 && MEMORY_HOTPLUG
1307 help
1308 This option enables a sysfs memory/probe interface for testing.
1309 See Documentation/memory-hotplug.txt for more information.
1310 If you are unsure how to answer this question, answer N.
1311
1312 config ARCH_PROC_KCORE_TEXT
1313 def_bool y
1314 depends on X86_64 && PROC_KCORE
1315
1316 config ILLEGAL_POINTER_VALUE
1317 hex
1318 default 0 if X86_32
1319 default 0xdead000000000000 if X86_64
1320
1321 source "mm/Kconfig"
1322
1323 config HIGHPTE
1324 bool "Allocate 3rd-level pagetables from highmem"
1325 depends on HIGHMEM
1326 ---help---
1327 The VM uses one page table entry for each page of physical memory.
1328 For systems with a lot of RAM, this can be wasteful of precious
1329 low memory. Setting this option will put user-space page table
1330 entries in high memory.
1331
1332 config X86_CHECK_BIOS_CORRUPTION
1333 bool "Check for low memory corruption"
1334 ---help---
1335 Periodically check for memory corruption in low memory, which
1336 is suspected to be caused by BIOS. Even when enabled in the
1337 configuration, it is disabled at runtime. Enable it by
1338 setting "memory_corruption_check=1" on the kernel command
1339 line. By default it scans the low 64k of memory every 60
1340 seconds; see the memory_corruption_check_size and
1341 memory_corruption_check_period parameters in
1342 Documentation/kernel-parameters.txt to adjust this.
1343
1344 When enabled with the default parameters, this option has
1345 almost no overhead, as it reserves a relatively small amount
1346 of memory and scans it infrequently. It both detects corruption
1347 and prevents it from affecting the running system.
1348
1349 It is, however, intended as a diagnostic tool; if repeatable
1350 BIOS-originated corruption always affects the same memory,
1351 you can use memmap= to prevent the kernel from using that
1352 memory.
1353
1354 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1355 bool "Set the default setting of memory_corruption_check"
1356 depends on X86_CHECK_BIOS_CORRUPTION
1357 default y
1358 ---help---
1359 Set whether the default state of memory_corruption_check is
1360 on or off.
1361
1362 config X86_RESERVE_LOW
1363 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1364 default 64
1365 range 4 640
1366 ---help---
1367 Specify the amount of low memory to reserve for the BIOS.
1368
1369 The first page contains BIOS data structures that the kernel
1370 must not use, so that page must always be reserved.
1371
1372 By default we reserve the first 64K of physical RAM, as a
1373 number of BIOSes are known to corrupt that memory range
1374 during events such as suspend/resume or monitor cable
1375 insertion, so it must not be used by the kernel.
1376
1377 You can set this to 4 if you are absolutely sure that you
1378 trust the BIOS to get all its memory reservations and usages
1379 right. If you know your BIOS have problems beyond the
1380 default 64K area, you can set this to 640 to avoid using the
1381 entire low memory range.
1382
1383 If you have doubts about the BIOS (e.g. suspend/resume does
1384 not work or there's kernel crashes after certain hardware
1385 hotplug events) then you might want to enable
1386 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1387 typical corruption patterns.
1388
1389 Leave this to the default value of 64 if you are unsure.
1390
1391 config MATH_EMULATION
1392 bool
1393 prompt "Math emulation" if X86_32
1394 ---help---
1395 Linux can emulate a math coprocessor (used for floating point
1396 operations) if you don't have one. 486DX and Pentium processors have
1397 a math coprocessor built in, 486SX and 386 do not, unless you added
1398 a 487DX or 387, respectively. (The messages during boot time can
1399 give you some hints here ["man dmesg"].) Everyone needs either a
1400 coprocessor or this emulation.
1401
1402 If you don't have a math coprocessor, you need to say Y here; if you
1403 say Y here even though you have a coprocessor, the coprocessor will
1404 be used nevertheless. (This behavior can be changed with the kernel
1405 command line option "no387", which comes handy if your coprocessor
1406 is broken. Try "man bootparam" or see the documentation of your boot
1407 loader (lilo or loadlin) about how to pass options to the kernel at
1408 boot time.) This means that it is a good idea to say Y here if you
1409 intend to use this kernel on different machines.
1410
1411 More information about the internals of the Linux math coprocessor
1412 emulation can be found in <file:arch/x86/math-emu/README>.
1413
1414 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1415 kernel, it won't hurt.
1416
1417 config MTRR
1418 def_bool y
1419 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1420 ---help---
1421 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1422 the Memory Type Range Registers (MTRRs) may be used to control
1423 processor access to memory ranges. This is most useful if you have
1424 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1425 allows bus write transfers to be combined into a larger transfer
1426 before bursting over the PCI/AGP bus. This can increase performance
1427 of image write operations 2.5 times or more. Saying Y here creates a
1428 /proc/mtrr file which may be used to manipulate your processor's
1429 MTRRs. Typically the X server should use this.
1430
1431 This code has a reasonably generic interface so that similar
1432 control registers on other processors can be easily supported
1433 as well:
1434
1435 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1436 Registers (ARRs) which provide a similar functionality to MTRRs. For
1437 these, the ARRs are used to emulate the MTRRs.
1438 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1439 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1440 write-combining. All of these processors are supported by this code
1441 and it makes sense to say Y here if you have one of them.
1442
1443 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1444 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1445 can lead to all sorts of problems, so it's good to say Y here.
1446
1447 You can safely say Y even if your machine doesn't have MTRRs, you'll
1448 just add about 9 KB to your kernel.
1449
1450 See <file:Documentation/x86/mtrr.txt> for more information.
1451
1452 config MTRR_SANITIZER
1453 def_bool y
1454 prompt "MTRR cleanup support"
1455 depends on MTRR
1456 ---help---
1457 Convert MTRR layout from continuous to discrete, so X drivers can
1458 add writeback entries.
1459
1460 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1461 The largest mtrr entry size for a continuous block can be set with
1462 mtrr_chunk_size.
1463
1464 If unsure, say Y.
1465
1466 config MTRR_SANITIZER_ENABLE_DEFAULT
1467 int "MTRR cleanup enable value (0-1)"
1468 range 0 1
1469 default "0"
1470 depends on MTRR_SANITIZER
1471 ---help---
1472 Enable mtrr cleanup default value
1473
1474 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1475 int "MTRR cleanup spare reg num (0-7)"
1476 range 0 7
1477 default "1"
1478 depends on MTRR_SANITIZER
1479 ---help---
1480 mtrr cleanup spare entries default, it can be changed via
1481 mtrr_spare_reg_nr=N on the kernel command line.
1482
1483 config X86_PAT
1484 def_bool y
1485 prompt "x86 PAT support" if EXPERT
1486 depends on MTRR
1487 ---help---
1488 Use PAT attributes to setup page level cache control.
1489
1490 PATs are the modern equivalents of MTRRs and are much more
1491 flexible than MTRRs.
1492
1493 Say N here if you see bootup problems (boot crash, boot hang,
1494 spontaneous reboots) or a non-working video driver.
1495
1496 If unsure, say Y.
1497
1498 config ARCH_USES_PG_UNCACHED
1499 def_bool y
1500 depends on X86_PAT
1501
1502 config ARCH_RANDOM
1503 def_bool y
1504 prompt "x86 architectural random number generator" if EXPERT
1505 ---help---
1506 Enable the x86 architectural RDRAND instruction
1507 (Intel Bull Mountain technology) to generate random numbers.
1508 If supported, this is a high bandwidth, cryptographically
1509 secure hardware random number generator.
1510
1511 config X86_SMAP
1512 def_bool y
1513 prompt "Supervisor Mode Access Prevention" if EXPERT
1514 ---help---
1515 Supervisor Mode Access Prevention (SMAP) is a security
1516 feature in newer Intel processors. There is a small
1517 performance cost if this enabled and turned on; there is
1518 also a small increase in the kernel size if this is enabled.
1519
1520 If unsure, say Y.
1521
1522 config EFI
1523 bool "EFI runtime service support"
1524 depends on ACPI
1525 select UCS2_STRING
1526 ---help---
1527 This enables the kernel to use EFI runtime services that are
1528 available (such as the EFI variable services).
1529
1530 This option is only useful on systems that have EFI firmware.
1531 In addition, you should use the latest ELILO loader available
1532 at <http://elilo.sourceforge.net> in order to take advantage
1533 of EFI runtime services. However, even with this option, the
1534 resultant kernel should continue to boot on existing non-EFI
1535 platforms.
1536
1537 config EFI_STUB
1538 bool "EFI stub support"
1539 depends on EFI
1540 ---help---
1541 This kernel feature allows a bzImage to be loaded directly
1542 by EFI firmware without the use of a bootloader.
1543
1544 See Documentation/efi-stub.txt for more information.
1545
1546 config EFI_MIXED
1547 bool "EFI mixed-mode support"
1548 depends on EFI_STUB && X86_64
1549 ---help---
1550 Enabling this feature allows a 64-bit kernel to be booted
1551 on a 32-bit firmware, provided that your CPU supports 64-bit
1552 mode.
1553
1554 Note that it is not possible to boot a mixed-mode enabled
1555 kernel via the EFI boot stub - a bootloader that supports
1556 the EFI handover protocol must be used.
1557
1558 If unsure, say N.
1559
1560 config SECCOMP
1561 def_bool y
1562 prompt "Enable seccomp to safely compute untrusted bytecode"
1563 ---help---
1564 This kernel feature is useful for number crunching applications
1565 that may need to compute untrusted bytecode during their
1566 execution. By using pipes or other transports made available to
1567 the process as file descriptors supporting the read/write
1568 syscalls, it's possible to isolate those applications in
1569 their own address space using seccomp. Once seccomp is
1570 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1571 and the task is only allowed to execute a few safe syscalls
1572 defined by each seccomp mode.
1573
1574 If unsure, say Y. Only embedded should say N here.
1575
1576 source kernel/Kconfig.hz
1577
1578 config KEXEC
1579 bool "kexec system call"
1580 ---help---
1581 kexec is a system call that implements the ability to shutdown your
1582 current kernel, and to start another kernel. It is like a reboot
1583 but it is independent of the system firmware. And like a reboot
1584 you can start any kernel with it, not just Linux.
1585
1586 The name comes from the similarity to the exec system call.
1587
1588 It is an ongoing process to be certain the hardware in a machine
1589 is properly shutdown, so do not be surprised if this code does not
1590 initially work for you. As of this writing the exact hardware
1591 interface is strongly in flux, so no good recommendation can be
1592 made.
1593
1594 config CRASH_DUMP
1595 bool "kernel crash dumps"
1596 depends on X86_64 || (X86_32 && HIGHMEM)
1597 ---help---
1598 Generate crash dump after being started by kexec.
1599 This should be normally only set in special crash dump kernels
1600 which are loaded in the main kernel with kexec-tools into
1601 a specially reserved region and then later executed after
1602 a crash by kdump/kexec. The crash dump kernel must be compiled
1603 to a memory address not used by the main kernel or BIOS using
1604 PHYSICAL_START, or it must be built as a relocatable image
1605 (CONFIG_RELOCATABLE=y).
1606 For more details see Documentation/kdump/kdump.txt
1607
1608 config KEXEC_JUMP
1609 bool "kexec jump"
1610 depends on KEXEC && HIBERNATION
1611 ---help---
1612 Jump between original kernel and kexeced kernel and invoke
1613 code in physical address mode via KEXEC
1614
1615 config PHYSICAL_START
1616 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1617 default "0x1000000"
1618 ---help---
1619 This gives the physical address where the kernel is loaded.
1620
1621 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1622 bzImage will decompress itself to above physical address and
1623 run from there. Otherwise, bzImage will run from the address where
1624 it has been loaded by the boot loader and will ignore above physical
1625 address.
1626
1627 In normal kdump cases one does not have to set/change this option
1628 as now bzImage can be compiled as a completely relocatable image
1629 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1630 address. This option is mainly useful for the folks who don't want
1631 to use a bzImage for capturing the crash dump and want to use a
1632 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1633 to be specifically compiled to run from a specific memory area
1634 (normally a reserved region) and this option comes handy.
1635
1636 So if you are using bzImage for capturing the crash dump,
1637 leave the value here unchanged to 0x1000000 and set
1638 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1639 for capturing the crash dump change this value to start of
1640 the reserved region. In other words, it can be set based on
1641 the "X" value as specified in the "crashkernel=YM@XM"
1642 command line boot parameter passed to the panic-ed
1643 kernel. Please take a look at Documentation/kdump/kdump.txt
1644 for more details about crash dumps.
1645
1646 Usage of bzImage for capturing the crash dump is recommended as
1647 one does not have to build two kernels. Same kernel can be used
1648 as production kernel and capture kernel. Above option should have
1649 gone away after relocatable bzImage support is introduced. But it
1650 is present because there are users out there who continue to use
1651 vmlinux for dump capture. This option should go away down the
1652 line.
1653
1654 Don't change this unless you know what you are doing.
1655
1656 config RELOCATABLE
1657 bool "Build a relocatable kernel"
1658 default y
1659 ---help---
1660 This builds a kernel image that retains relocation information
1661 so it can be loaded someplace besides the default 1MB.
1662 The relocations tend to make the kernel binary about 10% larger,
1663 but are discarded at runtime.
1664
1665 One use is for the kexec on panic case where the recovery kernel
1666 must live at a different physical address than the primary
1667 kernel.
1668
1669 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1670 it has been loaded at and the compile time physical address
1671 (CONFIG_PHYSICAL_START) is used as the minimum location.
1672
1673 config RANDOMIZE_BASE
1674 bool "Randomize the address of the kernel image"
1675 depends on RELOCATABLE
1676 default n
1677 ---help---
1678 Randomizes the physical and virtual address at which the
1679 kernel image is decompressed, as a security feature that
1680 deters exploit attempts relying on knowledge of the location
1681 of kernel internals.
1682
1683 Entropy is generated using the RDRAND instruction if it is
1684 supported. If RDTSC is supported, it is used as well. If
1685 neither RDRAND nor RDTSC are supported, then randomness is
1686 read from the i8254 timer.
1687
1688 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1689 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1690 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1691 minimum of 2MiB, only 10 bits of entropy is theoretically
1692 possible. At best, due to page table layouts, 64-bit can use
1693 9 bits of entropy and 32-bit uses 8 bits.
1694
1695 If unsure, say N.
1696
1697 config RANDOMIZE_BASE_MAX_OFFSET
1698 hex "Maximum kASLR offset allowed" if EXPERT
1699 depends on RANDOMIZE_BASE
1700 range 0x0 0x20000000 if X86_32
1701 default "0x20000000" if X86_32
1702 range 0x0 0x40000000 if X86_64
1703 default "0x40000000" if X86_64
1704 ---help---
1705 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1706 memory is used to determine the maximal offset in bytes that will
1707 be applied to the kernel when kernel Address Space Layout
1708 Randomization (kASLR) is active. This must be a multiple of
1709 PHYSICAL_ALIGN.
1710
1711 On 32-bit this is limited to 512MiB by page table layouts. The
1712 default is 512MiB.
1713
1714 On 64-bit this is limited by how the kernel fixmap page table is
1715 positioned, so this cannot be larger than 1GiB currently. Without
1716 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1717 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1718 modules area will shrink to compensate, up to the current maximum
1719 1GiB to 1GiB split. The default is 1GiB.
1720
1721 If unsure, leave at the default value.
1722
1723 # Relocation on x86 needs some additional build support
1724 config X86_NEED_RELOCS
1725 def_bool y
1726 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1727
1728 config PHYSICAL_ALIGN
1729 hex "Alignment value to which kernel should be aligned"
1730 default "0x200000"
1731 range 0x2000 0x1000000 if X86_32
1732 range 0x200000 0x1000000 if X86_64
1733 ---help---
1734 This value puts the alignment restrictions on physical address
1735 where kernel is loaded and run from. Kernel is compiled for an
1736 address which meets above alignment restriction.
1737
1738 If bootloader loads the kernel at a non-aligned address and
1739 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1740 address aligned to above value and run from there.
1741
1742 If bootloader loads the kernel at a non-aligned address and
1743 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1744 load address and decompress itself to the address it has been
1745 compiled for and run from there. The address for which kernel is
1746 compiled already meets above alignment restrictions. Hence the
1747 end result is that kernel runs from a physical address meeting
1748 above alignment restrictions.
1749
1750 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1751 this value must be a multiple of 0x200000.
1752
1753 Don't change this unless you know what you are doing.
1754
1755 config HOTPLUG_CPU
1756 bool "Support for hot-pluggable CPUs"
1757 depends on SMP
1758 ---help---
1759 Say Y here to allow turning CPUs off and on. CPUs can be
1760 controlled through /sys/devices/system/cpu.
1761 ( Note: power management support will enable this option
1762 automatically on SMP systems. )
1763 Say N if you want to disable CPU hotplug.
1764
1765 config BOOTPARAM_HOTPLUG_CPU0
1766 bool "Set default setting of cpu0_hotpluggable"
1767 default n
1768 depends on HOTPLUG_CPU
1769 ---help---
1770 Set whether default state of cpu0_hotpluggable is on or off.
1771
1772 Say Y here to enable CPU0 hotplug by default. If this switch
1773 is turned on, there is no need to give cpu0_hotplug kernel
1774 parameter and the CPU0 hotplug feature is enabled by default.
1775
1776 Please note: there are two known CPU0 dependencies if you want
1777 to enable the CPU0 hotplug feature either by this switch or by
1778 cpu0_hotplug kernel parameter.
1779
1780 First, resume from hibernate or suspend always starts from CPU0.
1781 So hibernate and suspend are prevented if CPU0 is offline.
1782
1783 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1784 offline if any interrupt can not migrate out of CPU0. There may
1785 be other CPU0 dependencies.
1786
1787 Please make sure the dependencies are under your control before
1788 you enable this feature.
1789
1790 Say N if you don't want to enable CPU0 hotplug feature by default.
1791 You still can enable the CPU0 hotplug feature at boot by kernel
1792 parameter cpu0_hotplug.
1793
1794 config DEBUG_HOTPLUG_CPU0
1795 def_bool n
1796 prompt "Debug CPU0 hotplug"
1797 depends on HOTPLUG_CPU
1798 ---help---
1799 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1800 soon as possible and boots up userspace with CPU0 offlined. User
1801 can online CPU0 back after boot time.
1802
1803 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1804 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1805 compilation or giving cpu0_hotplug kernel parameter at boot.
1806
1807 If unsure, say N.
1808
1809 config COMPAT_VDSO
1810 def_bool n
1811 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1812 depends on X86_32 || IA32_EMULATION
1813 ---help---
1814 Certain buggy versions of glibc will crash if they are
1815 presented with a 32-bit vDSO that is not mapped at the address
1816 indicated in its segment table.
1817
1818 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1819 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1820 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1821 the only released version with the bug, but OpenSUSE 9
1822 contains a buggy "glibc 2.3.2".
1823
1824 The symptom of the bug is that everything crashes on startup, saying:
1825 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1826
1827 Saying Y here changes the default value of the vdso32 boot
1828 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1829 This works around the glibc bug but hurts performance.
1830
1831 If unsure, say N: if you are compiling your own kernel, you
1832 are unlikely to be using a buggy version of glibc.
1833
1834 config CMDLINE_BOOL
1835 bool "Built-in kernel command line"
1836 ---help---
1837 Allow for specifying boot arguments to the kernel at
1838 build time. On some systems (e.g. embedded ones), it is
1839 necessary or convenient to provide some or all of the
1840 kernel boot arguments with the kernel itself (that is,
1841 to not rely on the boot loader to provide them.)
1842
1843 To compile command line arguments into the kernel,
1844 set this option to 'Y', then fill in the
1845 the boot arguments in CONFIG_CMDLINE.
1846
1847 Systems with fully functional boot loaders (i.e. non-embedded)
1848 should leave this option set to 'N'.
1849
1850 config CMDLINE
1851 string "Built-in kernel command string"
1852 depends on CMDLINE_BOOL
1853 default ""
1854 ---help---
1855 Enter arguments here that should be compiled into the kernel
1856 image and used at boot time. If the boot loader provides a
1857 command line at boot time, it is appended to this string to
1858 form the full kernel command line, when the system boots.
1859
1860 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1861 change this behavior.
1862
1863 In most cases, the command line (whether built-in or provided
1864 by the boot loader) should specify the device for the root
1865 file system.
1866
1867 config CMDLINE_OVERRIDE
1868 bool "Built-in command line overrides boot loader arguments"
1869 depends on CMDLINE_BOOL
1870 ---help---
1871 Set this option to 'Y' to have the kernel ignore the boot loader
1872 command line, and use ONLY the built-in command line.
1873
1874 This is used to work around broken boot loaders. This should
1875 be set to 'N' under normal conditions.
1876
1877 endmenu
1878
1879 config ARCH_ENABLE_MEMORY_HOTPLUG
1880 def_bool y
1881 depends on X86_64 || (X86_32 && HIGHMEM)
1882
1883 config ARCH_ENABLE_MEMORY_HOTREMOVE
1884 def_bool y
1885 depends on MEMORY_HOTPLUG
1886
1887 config USE_PERCPU_NUMA_NODE_ID
1888 def_bool y
1889 depends on NUMA
1890
1891 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1892 def_bool y
1893 depends on X86_64 || X86_PAE
1894
1895 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1896 def_bool y
1897 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1898
1899 menu "Power management and ACPI options"
1900
1901 config ARCH_HIBERNATION_HEADER
1902 def_bool y
1903 depends on X86_64 && HIBERNATION
1904
1905 source "kernel/power/Kconfig"
1906
1907 source "drivers/acpi/Kconfig"
1908
1909 source "drivers/sfi/Kconfig"
1910
1911 config X86_APM_BOOT
1912 def_bool y
1913 depends on APM
1914
1915 menuconfig APM
1916 tristate "APM (Advanced Power Management) BIOS support"
1917 depends on X86_32 && PM_SLEEP
1918 ---help---
1919 APM is a BIOS specification for saving power using several different
1920 techniques. This is mostly useful for battery powered laptops with
1921 APM compliant BIOSes. If you say Y here, the system time will be
1922 reset after a RESUME operation, the /proc/apm device will provide
1923 battery status information, and user-space programs will receive
1924 notification of APM "events" (e.g. battery status change).
1925
1926 If you select "Y" here, you can disable actual use of the APM
1927 BIOS by passing the "apm=off" option to the kernel at boot time.
1928
1929 Note that the APM support is almost completely disabled for
1930 machines with more than one CPU.
1931
1932 In order to use APM, you will need supporting software. For location
1933 and more information, read <file:Documentation/power/apm-acpi.txt>
1934 and the Battery Powered Linux mini-HOWTO, available from
1935 <http://www.tldp.org/docs.html#howto>.
1936
1937 This driver does not spin down disk drives (see the hdparm(8)
1938 manpage ("man 8 hdparm") for that), and it doesn't turn off
1939 VESA-compliant "green" monitors.
1940
1941 This driver does not support the TI 4000M TravelMate and the ACER
1942 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1943 desktop machines also don't have compliant BIOSes, and this driver
1944 may cause those machines to panic during the boot phase.
1945
1946 Generally, if you don't have a battery in your machine, there isn't
1947 much point in using this driver and you should say N. If you get
1948 random kernel OOPSes or reboots that don't seem to be related to
1949 anything, try disabling/enabling this option (or disabling/enabling
1950 APM in your BIOS).
1951
1952 Some other things you should try when experiencing seemingly random,
1953 "weird" problems:
1954
1955 1) make sure that you have enough swap space and that it is
1956 enabled.
1957 2) pass the "no-hlt" option to the kernel
1958 3) switch on floating point emulation in the kernel and pass
1959 the "no387" option to the kernel
1960 4) pass the "floppy=nodma" option to the kernel
1961 5) pass the "mem=4M" option to the kernel (thereby disabling
1962 all but the first 4 MB of RAM)
1963 6) make sure that the CPU is not over clocked.
1964 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1965 8) disable the cache from your BIOS settings
1966 9) install a fan for the video card or exchange video RAM
1967 10) install a better fan for the CPU
1968 11) exchange RAM chips
1969 12) exchange the motherboard.
1970
1971 To compile this driver as a module, choose M here: the
1972 module will be called apm.
1973
1974 if APM
1975
1976 config APM_IGNORE_USER_SUSPEND
1977 bool "Ignore USER SUSPEND"
1978 ---help---
1979 This option will ignore USER SUSPEND requests. On machines with a
1980 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1981 series notebooks, it is necessary to say Y because of a BIOS bug.
1982
1983 config APM_DO_ENABLE
1984 bool "Enable PM at boot time"
1985 ---help---
1986 Enable APM features at boot time. From page 36 of the APM BIOS
1987 specification: "When disabled, the APM BIOS does not automatically
1988 power manage devices, enter the Standby State, enter the Suspend
1989 State, or take power saving steps in response to CPU Idle calls."
1990 This driver will make CPU Idle calls when Linux is idle (unless this
1991 feature is turned off -- see "Do CPU IDLE calls", below). This
1992 should always save battery power, but more complicated APM features
1993 will be dependent on your BIOS implementation. You may need to turn
1994 this option off if your computer hangs at boot time when using APM
1995 support, or if it beeps continuously instead of suspending. Turn
1996 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1997 T400CDT. This is off by default since most machines do fine without
1998 this feature.
1999
2000 config APM_CPU_IDLE
2001 depends on CPU_IDLE
2002 bool "Make CPU Idle calls when idle"
2003 ---help---
2004 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2005 On some machines, this can activate improved power savings, such as
2006 a slowed CPU clock rate, when the machine is idle. These idle calls
2007 are made after the idle loop has run for some length of time (e.g.,
2008 333 mS). On some machines, this will cause a hang at boot time or
2009 whenever the CPU becomes idle. (On machines with more than one CPU,
2010 this option does nothing.)
2011
2012 config APM_DISPLAY_BLANK
2013 bool "Enable console blanking using APM"
2014 ---help---
2015 Enable console blanking using the APM. Some laptops can use this to
2016 turn off the LCD backlight when the screen blanker of the Linux
2017 virtual console blanks the screen. Note that this is only used by
2018 the virtual console screen blanker, and won't turn off the backlight
2019 when using the X Window system. This also doesn't have anything to
2020 do with your VESA-compliant power-saving monitor. Further, this
2021 option doesn't work for all laptops -- it might not turn off your
2022 backlight at all, or it might print a lot of errors to the console,
2023 especially if you are using gpm.
2024
2025 config APM_ALLOW_INTS
2026 bool "Allow interrupts during APM BIOS calls"
2027 ---help---
2028 Normally we disable external interrupts while we are making calls to
2029 the APM BIOS as a measure to lessen the effects of a badly behaving
2030 BIOS implementation. The BIOS should reenable interrupts if it
2031 needs to. Unfortunately, some BIOSes do not -- especially those in
2032 many of the newer IBM Thinkpads. If you experience hangs when you
2033 suspend, try setting this to Y. Otherwise, say N.
2034
2035 endif # APM
2036
2037 source "drivers/cpufreq/Kconfig"
2038
2039 source "drivers/cpuidle/Kconfig"
2040
2041 source "drivers/idle/Kconfig"
2042
2043 endmenu
2044
2045
2046 menu "Bus options (PCI etc.)"
2047
2048 config PCI
2049 bool "PCI support"
2050 default y
2051 ---help---
2052 Find out whether you have a PCI motherboard. PCI is the name of a
2053 bus system, i.e. the way the CPU talks to the other stuff inside
2054 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2055 VESA. If you have PCI, say Y, otherwise N.
2056
2057 choice
2058 prompt "PCI access mode"
2059 depends on X86_32 && PCI
2060 default PCI_GOANY
2061 ---help---
2062 On PCI systems, the BIOS can be used to detect the PCI devices and
2063 determine their configuration. However, some old PCI motherboards
2064 have BIOS bugs and may crash if this is done. Also, some embedded
2065 PCI-based systems don't have any BIOS at all. Linux can also try to
2066 detect the PCI hardware directly without using the BIOS.
2067
2068 With this option, you can specify how Linux should detect the
2069 PCI devices. If you choose "BIOS", the BIOS will be used,
2070 if you choose "Direct", the BIOS won't be used, and if you
2071 choose "MMConfig", then PCI Express MMCONFIG will be used.
2072 If you choose "Any", the kernel will try MMCONFIG, then the
2073 direct access method and falls back to the BIOS if that doesn't
2074 work. If unsure, go with the default, which is "Any".
2075
2076 config PCI_GOBIOS
2077 bool "BIOS"
2078
2079 config PCI_GOMMCONFIG
2080 bool "MMConfig"
2081
2082 config PCI_GODIRECT
2083 bool "Direct"
2084
2085 config PCI_GOOLPC
2086 bool "OLPC XO-1"
2087 depends on OLPC
2088
2089 config PCI_GOANY
2090 bool "Any"
2091
2092 endchoice
2093
2094 config PCI_BIOS
2095 def_bool y
2096 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2097
2098 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2099 config PCI_DIRECT
2100 def_bool y
2101 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2102
2103 config PCI_MMCONFIG
2104 def_bool y
2105 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2106
2107 config PCI_OLPC
2108 def_bool y
2109 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2110
2111 config PCI_XEN
2112 def_bool y
2113 depends on PCI && XEN
2114 select SWIOTLB_XEN
2115
2116 config PCI_DOMAINS
2117 def_bool y
2118 depends on PCI
2119
2120 config PCI_MMCONFIG
2121 bool "Support mmconfig PCI config space access"
2122 depends on X86_64 && PCI && ACPI
2123
2124 config PCI_CNB20LE_QUIRK
2125 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2126 depends on PCI
2127 help
2128 Read the PCI windows out of the CNB20LE host bridge. This allows
2129 PCI hotplug to work on systems with the CNB20LE chipset which do
2130 not have ACPI.
2131
2132 There's no public spec for this chipset, and this functionality
2133 is known to be incomplete.
2134
2135 You should say N unless you know you need this.
2136
2137 source "drivers/pci/pcie/Kconfig"
2138
2139 source "drivers/pci/Kconfig"
2140
2141 # x86_64 have no ISA slots, but can have ISA-style DMA.
2142 config ISA_DMA_API
2143 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2144 default y
2145 help
2146 Enables ISA-style DMA support for devices requiring such controllers.
2147 If unsure, say Y.
2148
2149 if X86_32
2150
2151 config ISA
2152 bool "ISA support"
2153 ---help---
2154 Find out whether you have ISA slots on your motherboard. ISA is the
2155 name of a bus system, i.e. the way the CPU talks to the other stuff
2156 inside your box. Other bus systems are PCI, EISA, MicroChannel
2157 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2158 newer boards don't support it. If you have ISA, say Y, otherwise N.
2159
2160 config EISA
2161 bool "EISA support"
2162 depends on ISA
2163 ---help---
2164 The Extended Industry Standard Architecture (EISA) bus was
2165 developed as an open alternative to the IBM MicroChannel bus.
2166
2167 The EISA bus provided some of the features of the IBM MicroChannel
2168 bus while maintaining backward compatibility with cards made for
2169 the older ISA bus. The EISA bus saw limited use between 1988 and
2170 1995 when it was made obsolete by the PCI bus.
2171
2172 Say Y here if you are building a kernel for an EISA-based machine.
2173
2174 Otherwise, say N.
2175
2176 source "drivers/eisa/Kconfig"
2177
2178 config SCx200
2179 tristate "NatSemi SCx200 support"
2180 ---help---
2181 This provides basic support for National Semiconductor's
2182 (now AMD's) Geode processors. The driver probes for the
2183 PCI-IDs of several on-chip devices, so its a good dependency
2184 for other scx200_* drivers.
2185
2186 If compiled as a module, the driver is named scx200.
2187
2188 config SCx200HR_TIMER
2189 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2190 depends on SCx200
2191 default y
2192 ---help---
2193 This driver provides a clocksource built upon the on-chip
2194 27MHz high-resolution timer. Its also a workaround for
2195 NSC Geode SC-1100's buggy TSC, which loses time when the
2196 processor goes idle (as is done by the scheduler). The
2197 other workaround is idle=poll boot option.
2198
2199 config OLPC
2200 bool "One Laptop Per Child support"
2201 depends on !X86_PAE
2202 select GPIOLIB
2203 select OF
2204 select OF_PROMTREE
2205 select IRQ_DOMAIN
2206 ---help---
2207 Add support for detecting the unique features of the OLPC
2208 XO hardware.
2209
2210 config OLPC_XO1_PM
2211 bool "OLPC XO-1 Power Management"
2212 depends on OLPC && MFD_CS5535 && PM_SLEEP
2213 select MFD_CORE
2214 ---help---
2215 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2216
2217 config OLPC_XO1_RTC
2218 bool "OLPC XO-1 Real Time Clock"
2219 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2220 ---help---
2221 Add support for the XO-1 real time clock, which can be used as a
2222 programmable wakeup source.
2223
2224 config OLPC_XO1_SCI
2225 bool "OLPC XO-1 SCI extras"
2226 depends on OLPC && OLPC_XO1_PM
2227 depends on INPUT=y
2228 select POWER_SUPPLY
2229 select GPIO_CS5535
2230 select MFD_CORE
2231 ---help---
2232 Add support for SCI-based features of the OLPC XO-1 laptop:
2233 - EC-driven system wakeups
2234 - Power button
2235 - Ebook switch
2236 - Lid switch
2237 - AC adapter status updates
2238 - Battery status updates
2239
2240 config OLPC_XO15_SCI
2241 bool "OLPC XO-1.5 SCI extras"
2242 depends on OLPC && ACPI
2243 select POWER_SUPPLY
2244 ---help---
2245 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2246 - EC-driven system wakeups
2247 - AC adapter status updates
2248 - Battery status updates
2249
2250 config ALIX
2251 bool "PCEngines ALIX System Support (LED setup)"
2252 select GPIOLIB
2253 ---help---
2254 This option enables system support for the PCEngines ALIX.
2255 At present this just sets up LEDs for GPIO control on
2256 ALIX2/3/6 boards. However, other system specific setup should
2257 get added here.
2258
2259 Note: You must still enable the drivers for GPIO and LED support
2260 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2261
2262 Note: You have to set alix.force=1 for boards with Award BIOS.
2263
2264 config NET5501
2265 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2266 select GPIOLIB
2267 ---help---
2268 This option enables system support for the Soekris Engineering net5501.
2269
2270 config GEOS
2271 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2272 select GPIOLIB
2273 depends on DMI
2274 ---help---
2275 This option enables system support for the Traverse Technologies GEOS.
2276
2277 config TS5500
2278 bool "Technologic Systems TS-5500 platform support"
2279 depends on MELAN
2280 select CHECK_SIGNATURE
2281 select NEW_LEDS
2282 select LEDS_CLASS
2283 ---help---
2284 This option enables system support for the Technologic Systems TS-5500.
2285
2286 endif # X86_32
2287
2288 config AMD_NB
2289 def_bool y
2290 depends on CPU_SUP_AMD && PCI
2291
2292 source "drivers/pcmcia/Kconfig"
2293
2294 source "drivers/pci/hotplug/Kconfig"
2295
2296 config RAPIDIO
2297 tristate "RapidIO support"
2298 depends on PCI
2299 default n
2300 help
2301 If enabled this option will include drivers and the core
2302 infrastructure code to support RapidIO interconnect devices.
2303
2304 source "drivers/rapidio/Kconfig"
2305
2306 config X86_SYSFB
2307 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2308 help
2309 Firmwares often provide initial graphics framebuffers so the BIOS,
2310 bootloader or kernel can show basic video-output during boot for
2311 user-guidance and debugging. Historically, x86 used the VESA BIOS
2312 Extensions and EFI-framebuffers for this, which are mostly limited
2313 to x86.
2314 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2315 framebuffers so the new generic system-framebuffer drivers can be
2316 used on x86. If the framebuffer is not compatible with the generic
2317 modes, it is adverticed as fallback platform framebuffer so legacy
2318 drivers like efifb, vesafb and uvesafb can pick it up.
2319 If this option is not selected, all system framebuffers are always
2320 marked as fallback platform framebuffers as usual.
2321
2322 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2323 not be able to pick up generic system framebuffers if this option
2324 is selected. You are highly encouraged to enable simplefb as
2325 replacement if you select this option. simplefb can correctly deal
2326 with generic system framebuffers. But you should still keep vesafb
2327 and others enabled as fallback if a system framebuffer is
2328 incompatible with simplefb.
2329
2330 If unsure, say Y.
2331
2332 endmenu
2333
2334
2335 menu "Executable file formats / Emulations"
2336
2337 source "fs/Kconfig.binfmt"
2338
2339 config IA32_EMULATION
2340 bool "IA32 Emulation"
2341 depends on X86_64
2342 select BINFMT_ELF
2343 select COMPAT_BINFMT_ELF
2344 select HAVE_UID16
2345 ---help---
2346 Include code to run legacy 32-bit programs under a
2347 64-bit kernel. You should likely turn this on, unless you're
2348 100% sure that you don't have any 32-bit programs left.
2349
2350 config IA32_AOUT
2351 tristate "IA32 a.out support"
2352 depends on IA32_EMULATION
2353 ---help---
2354 Support old a.out binaries in the 32bit emulation.
2355
2356 config X86_X32
2357 bool "x32 ABI for 64-bit mode"
2358 depends on X86_64 && IA32_EMULATION
2359 ---help---
2360 Include code to run binaries for the x32 native 32-bit ABI
2361 for 64-bit processors. An x32 process gets access to the
2362 full 64-bit register file and wide data path while leaving
2363 pointers at 32 bits for smaller memory footprint.
2364
2365 You will need a recent binutils (2.22 or later) with
2366 elf32_x86_64 support enabled to compile a kernel with this
2367 option set.
2368
2369 config COMPAT
2370 def_bool y
2371 depends on IA32_EMULATION || X86_X32
2372 select ARCH_WANT_OLD_COMPAT_IPC
2373
2374 if COMPAT
2375 config COMPAT_FOR_U64_ALIGNMENT
2376 def_bool y
2377
2378 config SYSVIPC_COMPAT
2379 def_bool y
2380 depends on SYSVIPC
2381
2382 config KEYS_COMPAT
2383 def_bool y
2384 depends on KEYS
2385 endif
2386
2387 endmenu
2388
2389
2390 config HAVE_ATOMIC_IOMAP
2391 def_bool y
2392 depends on X86_32
2393
2394 config X86_DEV_DMA_OPS
2395 bool
2396 depends on X86_64 || STA2X11
2397
2398 config X86_DMA_REMAP
2399 bool
2400 depends on STA2X11
2401
2402 config IOSF_MBI
2403 tristate
2404 default m
2405 depends on PCI
2406
2407 source "net/Kconfig"
2408
2409 source "drivers/Kconfig"
2410
2411 source "drivers/firmware/Kconfig"
2412
2413 source "fs/Kconfig"
2414
2415 source "arch/x86/Kconfig.debug"
2416
2417 source "security/Kconfig"
2418
2419 source "crypto/Kconfig"
2420
2421 source "arch/x86/kvm/Kconfig"
2422
2423 source "lib/Kconfig"
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