Merge 3.15-rc6 into staging-next.
[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
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 if !SWIOTLB
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
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 OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
125 select OLD_SIGACTION if X86_32
126 select COMPAT_OLD_SIGACTION if IA32_EMULATION
127 select RTC_LIB
128 select HAVE_DEBUG_STACKOVERFLOW
129 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
130 select HAVE_CC_STACKPROTECTOR
131 select GENERIC_CPU_AUTOPROBE
132 select HAVE_ARCH_AUDITSYSCALL
133
134 config INSTRUCTION_DECODER
135 def_bool y
136 depends on KPROBES || PERF_EVENTS || UPROBES
137
138 config OUTPUT_FORMAT
139 string
140 default "elf32-i386" if X86_32
141 default "elf64-x86-64" if X86_64
142
143 config ARCH_DEFCONFIG
144 string
145 default "arch/x86/configs/i386_defconfig" if X86_32
146 default "arch/x86/configs/x86_64_defconfig" if X86_64
147
148 config LOCKDEP_SUPPORT
149 def_bool y
150
151 config STACKTRACE_SUPPORT
152 def_bool y
153
154 config HAVE_LATENCYTOP_SUPPORT
155 def_bool y
156
157 config MMU
158 def_bool y
159
160 config SBUS
161 bool
162
163 config NEED_DMA_MAP_STATE
164 def_bool y
165 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
166
167 config NEED_SG_DMA_LENGTH
168 def_bool y
169
170 config GENERIC_ISA_DMA
171 def_bool y
172 depends on ISA_DMA_API
173
174 config GENERIC_BUG
175 def_bool y
176 depends on BUG
177 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
178
179 config GENERIC_BUG_RELATIVE_POINTERS
180 bool
181
182 config GENERIC_HWEIGHT
183 def_bool y
184
185 config ARCH_MAY_HAVE_PC_FDC
186 def_bool y
187 depends on ISA_DMA_API
188
189 config RWSEM_XCHGADD_ALGORITHM
190 def_bool y
191
192 config GENERIC_CALIBRATE_DELAY
193 def_bool y
194
195 config ARCH_HAS_CPU_RELAX
196 def_bool y
197
198 config ARCH_HAS_CACHE_LINE_SIZE
199 def_bool y
200
201 config HAVE_SETUP_PER_CPU_AREA
202 def_bool y
203
204 config NEED_PER_CPU_EMBED_FIRST_CHUNK
205 def_bool y
206
207 config NEED_PER_CPU_PAGE_FIRST_CHUNK
208 def_bool y
209
210 config ARCH_HIBERNATION_POSSIBLE
211 def_bool y
212
213 config ARCH_SUSPEND_POSSIBLE
214 def_bool y
215
216 config ARCH_WANT_HUGE_PMD_SHARE
217 def_bool y
218
219 config ARCH_WANT_GENERAL_HUGETLB
220 def_bool y
221
222 config ZONE_DMA32
223 bool
224 default X86_64
225
226 config AUDIT_ARCH
227 bool
228 default X86_64
229
230 config ARCH_SUPPORTS_OPTIMIZED_INLINING
231 def_bool y
232
233 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
234 def_bool y
235
236 config HAVE_INTEL_TXT
237 def_bool y
238 depends on INTEL_IOMMU && ACPI
239
240 config X86_32_SMP
241 def_bool y
242 depends on X86_32 && SMP
243
244 config X86_64_SMP
245 def_bool y
246 depends on X86_64 && SMP
247
248 config X86_HT
249 def_bool y
250 depends on SMP
251
252 config X86_32_LAZY_GS
253 def_bool y
254 depends on X86_32 && !CC_STACKPROTECTOR
255
256 config ARCH_HWEIGHT_CFLAGS
257 string
258 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
259 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
260
261 config ARCH_SUPPORTS_UPROBES
262 def_bool y
263
264 source "init/Kconfig"
265 source "kernel/Kconfig.freezer"
266
267 menu "Processor type and features"
268
269 config ZONE_DMA
270 bool "DMA memory allocation support" if EXPERT
271 default y
272 help
273 DMA memory allocation support allows devices with less than 32-bit
274 addressing to allocate within the first 16MB of address space.
275 Disable if no such devices will be used.
276
277 If unsure, say Y.
278
279 config SMP
280 bool "Symmetric multi-processing support"
281 ---help---
282 This enables support for systems with more than one CPU. If you have
283 a system with only one CPU, say N. If you have a system with more
284 than one CPU, say Y.
285
286 If you say N here, the kernel will run on uni- and multiprocessor
287 machines, but will use only one CPU of a multiprocessor machine. If
288 you say Y here, the kernel will run on many, but not all,
289 uniprocessor machines. On a uniprocessor machine, the kernel
290 will run faster if you say N here.
291
292 Note that if you say Y here and choose architecture "586" or
293 "Pentium" under "Processor family", the kernel will not work on 486
294 architectures. Similarly, multiprocessor kernels for the "PPro"
295 architecture may not work on all Pentium based boards.
296
297 People using multiprocessor machines who say Y here should also say
298 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
299 Management" code will be disabled if you say Y here.
300
301 See also <file:Documentation/x86/i386/IO-APIC.txt>,
302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
303 <http://www.tldp.org/docs.html#howto>.
304
305 If you don't know what to do here, say N.
306
307 config X86_X2APIC
308 bool "Support x2apic"
309 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
310 ---help---
311 This enables x2apic support on CPUs that have this feature.
312
313 This allows 32-bit apic IDs (so it can support very large systems),
314 and accesses the local apic via MSRs not via mmio.
315
316 If you don't know what to do here, say N.
317
318 config X86_MPPARSE
319 bool "Enable MPS table" if ACPI || SFI
320 default y
321 depends on X86_LOCAL_APIC
322 ---help---
323 For old smp systems that do not have proper acpi support. Newer systems
324 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
325
326 config X86_BIGSMP
327 bool "Support for big SMP systems with more than 8 CPUs"
328 depends on X86_32 && SMP
329 ---help---
330 This option is needed for the systems that have more than 8 CPUs
331
332 config GOLDFISH
333 def_bool y
334 depends on X86_GOLDFISH
335
336 if X86_32
337 config X86_EXTENDED_PLATFORM
338 bool "Support for extended (non-PC) x86 platforms"
339 default y
340 ---help---
341 If you disable this option then the kernel will only support
342 standard PC platforms. (which covers the vast majority of
343 systems out there.)
344
345 If you enable this option then you'll be able to select support
346 for the following (non-PC) 32 bit x86 platforms:
347 Goldfish (Android emulator)
348 AMD Elan
349 RDC R-321x SoC
350 SGI 320/540 (Visual Workstation)
351 STA2X11-based (e.g. Northville)
352 Moorestown MID devices
353
354 If you have one of these systems, or if you want to build a
355 generic distribution kernel, say Y here - otherwise say N.
356 endif
357
358 if X86_64
359 config X86_EXTENDED_PLATFORM
360 bool "Support for extended (non-PC) x86 platforms"
361 default y
362 ---help---
363 If you disable this option then the kernel will only support
364 standard PC platforms. (which covers the vast majority of
365 systems out there.)
366
367 If you enable this option then you'll be able to select support
368 for the following (non-PC) 64 bit x86 platforms:
369 Numascale NumaChip
370 ScaleMP vSMP
371 SGI Ultraviolet
372
373 If you have one of these systems, or if you want to build a
374 generic distribution kernel, say Y here - otherwise say N.
375 endif
376 # This is an alphabetically sorted list of 64 bit extended platforms
377 # Please maintain the alphabetic order if and when there are additions
378 config X86_NUMACHIP
379 bool "Numascale NumaChip"
380 depends on X86_64
381 depends on X86_EXTENDED_PLATFORM
382 depends on NUMA
383 depends on SMP
384 depends on X86_X2APIC
385 depends on PCI_MMCONFIG
386 ---help---
387 Adds support for Numascale NumaChip large-SMP systems. Needed to
388 enable more than ~168 cores.
389 If you don't have one of these, you should say N here.
390
391 config X86_VSMP
392 bool "ScaleMP vSMP"
393 select HYPERVISOR_GUEST
394 select PARAVIRT
395 depends on X86_64 && PCI
396 depends on X86_EXTENDED_PLATFORM
397 depends on SMP
398 ---help---
399 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
400 supposed to run on these EM64T-based machines. Only choose this option
401 if you have one of these machines.
402
403 config X86_UV
404 bool "SGI Ultraviolet"
405 depends on X86_64
406 depends on X86_EXTENDED_PLATFORM
407 depends on NUMA
408 depends on X86_X2APIC
409 ---help---
410 This option is needed in order to support SGI Ultraviolet systems.
411 If you don't have one of these, you should say N here.
412
413 # Following is an alphabetically sorted list of 32 bit extended platforms
414 # Please maintain the alphabetic order if and when there are additions
415
416 config X86_GOLDFISH
417 bool "Goldfish (Virtual Platform)"
418 depends on X86_EXTENDED_PLATFORM
419 ---help---
420 Enable support for the Goldfish virtual platform used primarily
421 for Android development. Unless you are building for the Android
422 Goldfish emulator say N here.
423
424 config X86_INTEL_CE
425 bool "CE4100 TV platform"
426 depends on PCI
427 depends on PCI_GODIRECT
428 depends on X86_32
429 depends on X86_EXTENDED_PLATFORM
430 select X86_REBOOTFIXUPS
431 select OF
432 select OF_EARLY_FLATTREE
433 select IRQ_DOMAIN
434 ---help---
435 Select for the Intel CE media processor (CE4100) SOC.
436 This option compiles in support for the CE4100 SOC for settop
437 boxes and media devices.
438
439 config X86_INTEL_MID
440 bool "Intel MID platform support"
441 depends on X86_32
442 depends on X86_EXTENDED_PLATFORM
443 depends on X86_PLATFORM_DEVICES
444 depends on PCI
445 depends on PCI_GOANY
446 depends on X86_IO_APIC
447 select SFI
448 select I2C
449 select DW_APB_TIMER
450 select APB_TIMER
451 select INTEL_SCU_IPC
452 select MFD_INTEL_MSIC
453 ---help---
454 Select to build a kernel capable of supporting Intel MID (Mobile
455 Internet Device) platform systems which do not have the PCI legacy
456 interfaces. If you are building for a PC class system say N here.
457
458 Intel MID platforms are based on an Intel processor and chipset which
459 consume less power than most of the x86 derivatives.
460
461 config X86_INTEL_LPSS
462 bool "Intel Low Power Subsystem Support"
463 depends on ACPI
464 select COMMON_CLK
465 select PINCTRL
466 ---help---
467 Select to build support for Intel Low Power Subsystem such as
468 found on Intel Lynxpoint PCH. Selecting this option enables
469 things like clock tree (common clock framework) and pincontrol
470 which are needed by the LPSS peripheral drivers.
471
472 config X86_RDC321X
473 bool "RDC R-321x SoC"
474 depends on X86_32
475 depends on X86_EXTENDED_PLATFORM
476 select M486
477 select X86_REBOOTFIXUPS
478 ---help---
479 This option is needed for RDC R-321x system-on-chip, also known
480 as R-8610-(G).
481 If you don't have one of these chips, you should say N here.
482
483 config X86_32_NON_STANDARD
484 bool "Support non-standard 32-bit SMP architectures"
485 depends on X86_32 && SMP
486 depends on X86_EXTENDED_PLATFORM
487 ---help---
488 This option compiles in the bigsmp and STA2X11 default
489 subarchitectures. It is intended for a generic binary
490 kernel. If you select them all, kernel will probe it one by
491 one and will fallback to default.
492
493 # Alphabetically sorted list of Non standard 32 bit platforms
494
495 config X86_SUPPORTS_MEMORY_FAILURE
496 def_bool y
497 # MCE code calls memory_failure():
498 depends on X86_MCE
499 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
500 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
501 depends on X86_64 || !SPARSEMEM
502 select ARCH_SUPPORTS_MEMORY_FAILURE
503
504 config STA2X11
505 bool "STA2X11 Companion Chip Support"
506 depends on X86_32_NON_STANDARD && PCI
507 select X86_DEV_DMA_OPS
508 select X86_DMA_REMAP
509 select SWIOTLB
510 select MFD_STA2X11
511 select ARCH_REQUIRE_GPIOLIB
512 default n
513 ---help---
514 This adds support for boards based on the STA2X11 IO-Hub,
515 a.k.a. "ConneXt". The chip is used in place of the standard
516 PC chipset, so all "standard" peripherals are missing. If this
517 option is selected the kernel will still be able to boot on
518 standard PC machines.
519
520 config X86_32_IRIS
521 tristate "Eurobraille/Iris poweroff module"
522 depends on X86_32
523 ---help---
524 The Iris machines from EuroBraille do not have APM or ACPI support
525 to shut themselves down properly. A special I/O sequence is
526 needed to do so, which is what this module does at
527 kernel shutdown.
528
529 This is only for Iris machines from EuroBraille.
530
531 If unused, say N.
532
533 config SCHED_OMIT_FRAME_POINTER
534 def_bool y
535 prompt "Single-depth WCHAN output"
536 depends on X86
537 ---help---
538 Calculate simpler /proc/<PID>/wchan values. If this option
539 is disabled then wchan values will recurse back to the
540 caller function. This provides more accurate wchan values,
541 at the expense of slightly more scheduling overhead.
542
543 If in doubt, say "Y".
544
545 menuconfig HYPERVISOR_GUEST
546 bool "Linux guest support"
547 ---help---
548 Say Y here to enable options for running Linux under various hyper-
549 visors. This option enables basic hypervisor detection and platform
550 setup.
551
552 If you say N, all options in this submenu will be skipped and
553 disabled, and Linux guest support won't be built in.
554
555 if HYPERVISOR_GUEST
556
557 config PARAVIRT
558 bool "Enable paravirtualization code"
559 ---help---
560 This changes the kernel so it can modify itself when it is run
561 under a hypervisor, potentially improving performance significantly
562 over full virtualization. However, when run without a hypervisor
563 the kernel is theoretically slower and slightly larger.
564
565 config PARAVIRT_DEBUG
566 bool "paravirt-ops debugging"
567 depends on PARAVIRT && DEBUG_KERNEL
568 ---help---
569 Enable to debug paravirt_ops internals. Specifically, BUG if
570 a paravirt_op is missing when it is called.
571
572 config PARAVIRT_SPINLOCKS
573 bool "Paravirtualization layer for spinlocks"
574 depends on PARAVIRT && SMP
575 select UNINLINE_SPIN_UNLOCK
576 ---help---
577 Paravirtualized spinlocks allow a pvops backend to replace the
578 spinlock implementation with something virtualization-friendly
579 (for example, block the virtual CPU rather than spinning).
580
581 It has a minimal impact on native kernels and gives a nice performance
582 benefit on paravirtualized KVM / Xen kernels.
583
584 If you are unsure how to answer this question, answer Y.
585
586 source "arch/x86/xen/Kconfig"
587
588 config KVM_GUEST
589 bool "KVM Guest support (including kvmclock)"
590 depends on PARAVIRT
591 select PARAVIRT_CLOCK
592 default y
593 ---help---
594 This option enables various optimizations for running under the KVM
595 hypervisor. It includes a paravirtualized clock, so that instead
596 of relying on a PIT (or probably other) emulation by the
597 underlying device model, the host provides the guest with
598 timing infrastructure such as time of day, and system time
599
600 config KVM_DEBUG_FS
601 bool "Enable debug information for KVM Guests in debugfs"
602 depends on KVM_GUEST && DEBUG_FS
603 default n
604 ---help---
605 This option enables collection of various statistics for KVM guest.
606 Statistics are displayed in debugfs filesystem. Enabling this option
607 may incur significant overhead.
608
609 source "arch/x86/lguest/Kconfig"
610
611 config PARAVIRT_TIME_ACCOUNTING
612 bool "Paravirtual steal time accounting"
613 depends on PARAVIRT
614 default n
615 ---help---
616 Select this option to enable fine granularity task steal time
617 accounting. Time spent executing other tasks in parallel with
618 the current vCPU is discounted from the vCPU power. To account for
619 that, there can be a small performance impact.
620
621 If in doubt, say N here.
622
623 config PARAVIRT_CLOCK
624 bool
625
626 endif #HYPERVISOR_GUEST
627
628 config NO_BOOTMEM
629 def_bool y
630
631 config MEMTEST
632 bool "Memtest"
633 ---help---
634 This option adds a kernel parameter 'memtest', which allows memtest
635 to be set.
636 memtest=0, mean disabled; -- default
637 memtest=1, mean do 1 test pattern;
638 ...
639 memtest=4, mean do 4 test patterns.
640 If you are unsure how to answer this question, answer N.
641
642 source "arch/x86/Kconfig.cpu"
643
644 config HPET_TIMER
645 def_bool X86_64
646 prompt "HPET Timer Support" if X86_32
647 ---help---
648 Use the IA-PC HPET (High Precision Event Timer) to manage
649 time in preference to the PIT and RTC, if a HPET is
650 present.
651 HPET is the next generation timer replacing legacy 8254s.
652 The HPET provides a stable time base on SMP
653 systems, unlike the TSC, but it is more expensive to access,
654 as it is off-chip. You can find the HPET spec at
655 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
656
657 You can safely choose Y here. However, HPET will only be
658 activated if the platform and the BIOS support this feature.
659 Otherwise the 8254 will be used for timing services.
660
661 Choose N to continue using the legacy 8254 timer.
662
663 config HPET_EMULATE_RTC
664 def_bool y
665 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
666
667 config APB_TIMER
668 def_bool y if X86_INTEL_MID
669 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
670 select DW_APB_TIMER
671 depends on X86_INTEL_MID && SFI
672 help
673 APB timer is the replacement for 8254, HPET on X86 MID platforms.
674 The APBT provides a stable time base on SMP
675 systems, unlike the TSC, but it is more expensive to access,
676 as it is off-chip. APB timers are always running regardless of CPU
677 C states, they are used as per CPU clockevent device when possible.
678
679 # Mark as expert because too many people got it wrong.
680 # The code disables itself when not needed.
681 config DMI
682 default y
683 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
684 bool "Enable DMI scanning" if EXPERT
685 ---help---
686 Enabled scanning of DMI to identify machine quirks. Say Y
687 here unless you have verified that your setup is not
688 affected by entries in the DMI blacklist. Required by PNP
689 BIOS code.
690
691 config GART_IOMMU
692 bool "Old AMD GART IOMMU support"
693 select SWIOTLB
694 depends on X86_64 && PCI && AMD_NB
695 ---help---
696 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
697 GART based hardware IOMMUs.
698
699 The GART supports full DMA access for devices with 32-bit access
700 limitations, on systems with more than 3 GB. This is usually needed
701 for USB, sound, many IDE/SATA chipsets and some other devices.
702
703 Newer systems typically have a modern AMD IOMMU, supported via
704 the CONFIG_AMD_IOMMU=y config option.
705
706 In normal configurations this driver is only active when needed:
707 there's more than 3 GB of memory and the system contains a
708 32-bit limited device.
709
710 If unsure, say Y.
711
712 config CALGARY_IOMMU
713 bool "IBM Calgary IOMMU support"
714 select SWIOTLB
715 depends on X86_64 && PCI
716 ---help---
717 Support for hardware IOMMUs in IBM's xSeries x366 and x460
718 systems. Needed to run systems with more than 3GB of memory
719 properly with 32-bit PCI devices that do not support DAC
720 (Double Address Cycle). Calgary also supports bus level
721 isolation, where all DMAs pass through the IOMMU. This
722 prevents them from going anywhere except their intended
723 destination. This catches hard-to-find kernel bugs and
724 mis-behaving drivers and devices that do not use the DMA-API
725 properly to set up their DMA buffers. The IOMMU can be
726 turned off at boot time with the iommu=off parameter.
727 Normally the kernel will make the right choice by itself.
728 If unsure, say Y.
729
730 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
731 def_bool y
732 prompt "Should Calgary be enabled by default?"
733 depends on CALGARY_IOMMU
734 ---help---
735 Should Calgary be enabled by default? if you choose 'y', Calgary
736 will be used (if it exists). If you choose 'n', Calgary will not be
737 used even if it exists. If you choose 'n' and would like to use
738 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
739 If unsure, say Y.
740
741 # need this always selected by IOMMU for the VIA workaround
742 config SWIOTLB
743 def_bool y if X86_64
744 ---help---
745 Support for software bounce buffers used on x86-64 systems
746 which don't have a hardware IOMMU. Using this PCI devices
747 which can only access 32-bits of memory can be used on systems
748 with more than 3 GB of memory.
749 If unsure, say Y.
750
751 config IOMMU_HELPER
752 def_bool y
753 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
754
755 config MAXSMP
756 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
757 depends on X86_64 && SMP && DEBUG_KERNEL
758 select CPUMASK_OFFSTACK
759 ---help---
760 Enable maximum number of CPUS and NUMA Nodes for this architecture.
761 If unsure, say N.
762
763 config NR_CPUS
764 int "Maximum number of CPUs" if SMP && !MAXSMP
765 range 2 8 if SMP && X86_32 && !X86_BIGSMP
766 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
767 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
768 default "1" if !SMP
769 default "8192" if MAXSMP
770 default "32" if SMP && X86_BIGSMP
771 default "8" if SMP
772 ---help---
773 This allows you to specify the maximum number of CPUs which this
774 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
775 supported value is 4096, otherwise the maximum value is 512. The
776 minimum value which makes sense is 2.
777
778 This is purely to save memory - each supported CPU adds
779 approximately eight kilobytes to the kernel image.
780
781 config SCHED_SMT
782 bool "SMT (Hyperthreading) scheduler support"
783 depends on X86_HT
784 ---help---
785 SMT scheduler support improves the CPU scheduler's decision making
786 when dealing with Intel Pentium 4 chips with HyperThreading at a
787 cost of slightly increased overhead in some places. If unsure say
788 N here.
789
790 config SCHED_MC
791 def_bool y
792 prompt "Multi-core scheduler support"
793 depends on X86_HT
794 ---help---
795 Multi-core scheduler support improves the CPU scheduler's decision
796 making when dealing with multi-core CPU chips at a cost of slightly
797 increased overhead in some places. If unsure say N here.
798
799 source "kernel/Kconfig.preempt"
800
801 config X86_UP_APIC
802 bool "Local APIC support on uniprocessors"
803 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
804 ---help---
805 A local APIC (Advanced Programmable Interrupt Controller) is an
806 integrated interrupt controller in the CPU. If you have a single-CPU
807 system which has a processor with a local APIC, you can say Y here to
808 enable and use it. If you say Y here even though your machine doesn't
809 have a local APIC, then the kernel will still run with no slowdown at
810 all. The local APIC supports CPU-generated self-interrupts (timer,
811 performance counters), and the NMI watchdog which detects hard
812 lockups.
813
814 config X86_UP_IOAPIC
815 bool "IO-APIC support on uniprocessors"
816 depends on X86_UP_APIC
817 ---help---
818 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
819 SMP-capable replacement for PC-style interrupt controllers. Most
820 SMP systems and many recent uniprocessor systems have one.
821
822 If you have a single-CPU system with an IO-APIC, you can say Y here
823 to use it. If you say Y here even though your machine doesn't have
824 an IO-APIC, then the kernel will still run with no slowdown at all.
825
826 config X86_LOCAL_APIC
827 def_bool y
828 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
829
830 config X86_IO_APIC
831 def_bool y
832 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
833
834 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
835 bool "Reroute for broken boot IRQs"
836 depends on X86_IO_APIC
837 ---help---
838 This option enables a workaround that fixes a source of
839 spurious interrupts. This is recommended when threaded
840 interrupt handling is used on systems where the generation of
841 superfluous "boot interrupts" cannot be disabled.
842
843 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
844 entry in the chipset's IO-APIC is masked (as, e.g. the RT
845 kernel does during interrupt handling). On chipsets where this
846 boot IRQ generation cannot be disabled, this workaround keeps
847 the original IRQ line masked so that only the equivalent "boot
848 IRQ" is delivered to the CPUs. The workaround also tells the
849 kernel to set up the IRQ handler on the boot IRQ line. In this
850 way only one interrupt is delivered to the kernel. Otherwise
851 the spurious second interrupt may cause the kernel to bring
852 down (vital) interrupt lines.
853
854 Only affects "broken" chipsets. Interrupt sharing may be
855 increased on these systems.
856
857 config X86_MCE
858 bool "Machine Check / overheating reporting"
859 default y
860 ---help---
861 Machine Check support allows the processor to notify the
862 kernel if it detects a problem (e.g. overheating, data corruption).
863 The action the kernel takes depends on the severity of the problem,
864 ranging from warning messages to halting the machine.
865
866 config X86_MCE_INTEL
867 def_bool y
868 prompt "Intel MCE features"
869 depends on X86_MCE && X86_LOCAL_APIC
870 ---help---
871 Additional support for intel specific MCE features such as
872 the thermal monitor.
873
874 config X86_MCE_AMD
875 def_bool y
876 prompt "AMD MCE features"
877 depends on X86_MCE && X86_LOCAL_APIC
878 ---help---
879 Additional support for AMD specific MCE features such as
880 the DRAM Error Threshold.
881
882 config X86_ANCIENT_MCE
883 bool "Support for old Pentium 5 / WinChip machine checks"
884 depends on X86_32 && X86_MCE
885 ---help---
886 Include support for machine check handling on old Pentium 5 or WinChip
887 systems. These typically need to be enabled explicitly on the command
888 line.
889
890 config X86_MCE_THRESHOLD
891 depends on X86_MCE_AMD || X86_MCE_INTEL
892 def_bool y
893
894 config X86_MCE_INJECT
895 depends on X86_MCE
896 tristate "Machine check injector support"
897 ---help---
898 Provide support for injecting machine checks for testing purposes.
899 If you don't know what a machine check is and you don't do kernel
900 QA it is safe to say n.
901
902 config X86_THERMAL_VECTOR
903 def_bool y
904 depends on X86_MCE_INTEL
905
906 config VM86
907 bool "Enable VM86 support" if EXPERT
908 default y
909 depends on X86_32
910 ---help---
911 This option is required by programs like DOSEMU to run 16-bit legacy
912 code on X86 processors. It also may be needed by software like
913 XFree86 to initialize some video cards via BIOS. Disabling this
914 option saves about 6k.
915
916 config TOSHIBA
917 tristate "Toshiba Laptop support"
918 depends on X86_32
919 ---help---
920 This adds a driver to safely access the System Management Mode of
921 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
922 not work on models with a Phoenix BIOS. The System Management Mode
923 is used to set the BIOS and power saving options on Toshiba portables.
924
925 For information on utilities to make use of this driver see the
926 Toshiba Linux utilities web site at:
927 <http://www.buzzard.org.uk/toshiba/>.
928
929 Say Y if you intend to run this kernel on a Toshiba portable.
930 Say N otherwise.
931
932 config I8K
933 tristate "Dell laptop support"
934 select HWMON
935 ---help---
936 This adds a driver to safely access the System Management Mode
937 of the CPU on the Dell Inspiron 8000. The System Management Mode
938 is used to read cpu temperature and cooling fan status and to
939 control the fans on the I8K portables.
940
941 This driver has been tested only on the Inspiron 8000 but it may
942 also work with other Dell laptops. You can force loading on other
943 models by passing the parameter `force=1' to the module. Use at
944 your own risk.
945
946 For information on utilities to make use of this driver see the
947 I8K Linux utilities web site at:
948 <http://people.debian.org/~dz/i8k/>
949
950 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
951 Say N otherwise.
952
953 config X86_REBOOTFIXUPS
954 bool "Enable X86 board specific fixups for reboot"
955 depends on X86_32
956 ---help---
957 This enables chipset and/or board specific fixups to be done
958 in order to get reboot to work correctly. This is only needed on
959 some combinations of hardware and BIOS. The symptom, for which
960 this config is intended, is when reboot ends with a stalled/hung
961 system.
962
963 Currently, the only fixup is for the Geode machines using
964 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
965
966 Say Y if you want to enable the fixup. Currently, it's safe to
967 enable this option even if you don't need it.
968 Say N otherwise.
969
970 config MICROCODE
971 tristate "CPU microcode loading support"
972 depends on CPU_SUP_AMD || CPU_SUP_INTEL
973 select FW_LOADER
974 ---help---
975
976 If you say Y here, you will be able to update the microcode on
977 certain Intel and AMD processors. The Intel support is for the
978 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
979 Xeon etc. The AMD support is for families 0x10 and later. You will
980 obviously need the actual microcode binary data itself which is not
981 shipped with the Linux kernel.
982
983 This option selects the general module only, you need to select
984 at least one vendor specific module as well.
985
986 To compile this driver as a module, choose M here: the module
987 will be called microcode.
988
989 config MICROCODE_INTEL
990 bool "Intel microcode loading support"
991 depends on MICROCODE
992 default MICROCODE
993 select FW_LOADER
994 ---help---
995 This options enables microcode patch loading support for Intel
996 processors.
997
998 For the current Intel microcode data package go to
999 <https://downloadcenter.intel.com> and search for
1000 'Linux Processor Microcode Data File'.
1001
1002 config MICROCODE_AMD
1003 bool "AMD microcode loading support"
1004 depends on MICROCODE
1005 select FW_LOADER
1006 ---help---
1007 If you select this option, microcode patch loading support for AMD
1008 processors will be enabled.
1009
1010 config MICROCODE_OLD_INTERFACE
1011 def_bool y
1012 depends on MICROCODE
1013
1014 config MICROCODE_INTEL_EARLY
1015 def_bool n
1016
1017 config MICROCODE_AMD_EARLY
1018 def_bool n
1019
1020 config MICROCODE_EARLY
1021 bool "Early load microcode"
1022 depends on MICROCODE=y && BLK_DEV_INITRD
1023 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1024 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1025 default y
1026 help
1027 This option provides functionality to read additional microcode data
1028 at the beginning of initrd image. The data tells kernel to load
1029 microcode to CPU's as early as possible. No functional change if no
1030 microcode data is glued to the initrd, therefore it's safe to say Y.
1031
1032 config X86_MSR
1033 tristate "/dev/cpu/*/msr - Model-specific register support"
1034 ---help---
1035 This device gives privileged processes access to the x86
1036 Model-Specific Registers (MSRs). It is a character device with
1037 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1038 MSR accesses are directed to a specific CPU on multi-processor
1039 systems.
1040
1041 config X86_CPUID
1042 tristate "/dev/cpu/*/cpuid - CPU information support"
1043 ---help---
1044 This device gives processes access to the x86 CPUID instruction to
1045 be executed on a specific processor. It is a character device
1046 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1047 /dev/cpu/31/cpuid.
1048
1049 choice
1050 prompt "High Memory Support"
1051 default HIGHMEM4G
1052 depends on X86_32
1053
1054 config NOHIGHMEM
1055 bool "off"
1056 ---help---
1057 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1058 However, the address space of 32-bit x86 processors is only 4
1059 Gigabytes large. That means that, if you have a large amount of
1060 physical memory, not all of it can be "permanently mapped" by the
1061 kernel. The physical memory that's not permanently mapped is called
1062 "high memory".
1063
1064 If you are compiling a kernel which will never run on a machine with
1065 more than 1 Gigabyte total physical RAM, answer "off" here (default
1066 choice and suitable for most users). This will result in a "3GB/1GB"
1067 split: 3GB are mapped so that each process sees a 3GB virtual memory
1068 space and the remaining part of the 4GB virtual memory space is used
1069 by the kernel to permanently map as much physical memory as
1070 possible.
1071
1072 If the machine has between 1 and 4 Gigabytes physical RAM, then
1073 answer "4GB" here.
1074
1075 If more than 4 Gigabytes is used then answer "64GB" here. This
1076 selection turns Intel PAE (Physical Address Extension) mode on.
1077 PAE implements 3-level paging on IA32 processors. PAE is fully
1078 supported by Linux, PAE mode is implemented on all recent Intel
1079 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1080 then the kernel will not boot on CPUs that don't support PAE!
1081
1082 The actual amount of total physical memory will either be
1083 auto detected or can be forced by using a kernel command line option
1084 such as "mem=256M". (Try "man bootparam" or see the documentation of
1085 your boot loader (lilo or loadlin) about how to pass options to the
1086 kernel at boot time.)
1087
1088 If unsure, say "off".
1089
1090 config HIGHMEM4G
1091 bool "4GB"
1092 ---help---
1093 Select this if you have a 32-bit processor and between 1 and 4
1094 gigabytes of physical RAM.
1095
1096 config HIGHMEM64G
1097 bool "64GB"
1098 depends on !M486
1099 select X86_PAE
1100 ---help---
1101 Select this if you have a 32-bit processor and more than 4
1102 gigabytes of physical RAM.
1103
1104 endchoice
1105
1106 choice
1107 prompt "Memory split" if EXPERT
1108 default VMSPLIT_3G
1109 depends on X86_32
1110 ---help---
1111 Select the desired split between kernel and user memory.
1112
1113 If the address range available to the kernel is less than the
1114 physical memory installed, the remaining memory will be available
1115 as "high memory". Accessing high memory is a little more costly
1116 than low memory, as it needs to be mapped into the kernel first.
1117 Note that increasing the kernel address space limits the range
1118 available to user programs, making the address space there
1119 tighter. Selecting anything other than the default 3G/1G split
1120 will also likely make your kernel incompatible with binary-only
1121 kernel modules.
1122
1123 If you are not absolutely sure what you are doing, leave this
1124 option alone!
1125
1126 config VMSPLIT_3G
1127 bool "3G/1G user/kernel split"
1128 config VMSPLIT_3G_OPT
1129 depends on !X86_PAE
1130 bool "3G/1G user/kernel split (for full 1G low memory)"
1131 config VMSPLIT_2G
1132 bool "2G/2G user/kernel split"
1133 config VMSPLIT_2G_OPT
1134 depends on !X86_PAE
1135 bool "2G/2G user/kernel split (for full 2G low memory)"
1136 config VMSPLIT_1G
1137 bool "1G/3G user/kernel split"
1138 endchoice
1139
1140 config PAGE_OFFSET
1141 hex
1142 default 0xB0000000 if VMSPLIT_3G_OPT
1143 default 0x80000000 if VMSPLIT_2G
1144 default 0x78000000 if VMSPLIT_2G_OPT
1145 default 0x40000000 if VMSPLIT_1G
1146 default 0xC0000000
1147 depends on X86_32
1148
1149 config HIGHMEM
1150 def_bool y
1151 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1152
1153 config X86_PAE
1154 bool "PAE (Physical Address Extension) Support"
1155 depends on X86_32 && !HIGHMEM4G
1156 ---help---
1157 PAE is required for NX support, and furthermore enables
1158 larger swapspace support for non-overcommit purposes. It
1159 has the cost of more pagetable lookup overhead, and also
1160 consumes more pagetable space per process.
1161
1162 config ARCH_PHYS_ADDR_T_64BIT
1163 def_bool y
1164 depends on X86_64 || X86_PAE
1165
1166 config ARCH_DMA_ADDR_T_64BIT
1167 def_bool y
1168 depends on X86_64 || HIGHMEM64G
1169
1170 config DIRECT_GBPAGES
1171 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1172 default y
1173 depends on X86_64
1174 ---help---
1175 Allow the kernel linear mapping to use 1GB pages on CPUs that
1176 support it. This can improve the kernel's performance a tiny bit by
1177 reducing TLB pressure. If in doubt, say "Y".
1178
1179 # Common NUMA Features
1180 config NUMA
1181 bool "Numa Memory Allocation and Scheduler Support"
1182 depends on SMP
1183 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1184 default y if X86_BIGSMP
1185 ---help---
1186 Enable NUMA (Non Uniform Memory Access) support.
1187
1188 The kernel will try to allocate memory used by a CPU on the
1189 local memory controller of the CPU and add some more
1190 NUMA awareness to the kernel.
1191
1192 For 64-bit this is recommended if the system is Intel Core i7
1193 (or later), AMD Opteron, or EM64T NUMA.
1194
1195 For 32-bit this is only needed if you boot a 32-bit
1196 kernel on a 64-bit NUMA platform.
1197
1198 Otherwise, you should say N.
1199
1200 config AMD_NUMA
1201 def_bool y
1202 prompt "Old style AMD Opteron NUMA detection"
1203 depends on X86_64 && NUMA && PCI
1204 ---help---
1205 Enable AMD NUMA node topology detection. You should say Y here if
1206 you have a multi processor AMD system. This uses an old method to
1207 read the NUMA configuration directly from the builtin Northbridge
1208 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1209 which also takes priority if both are compiled in.
1210
1211 config X86_64_ACPI_NUMA
1212 def_bool y
1213 prompt "ACPI NUMA detection"
1214 depends on X86_64 && NUMA && ACPI && PCI
1215 select ACPI_NUMA
1216 ---help---
1217 Enable ACPI SRAT based node topology detection.
1218
1219 # Some NUMA nodes have memory ranges that span
1220 # other nodes. Even though a pfn is valid and
1221 # between a node's start and end pfns, it may not
1222 # reside on that node. See memmap_init_zone()
1223 # for details.
1224 config NODES_SPAN_OTHER_NODES
1225 def_bool y
1226 depends on X86_64_ACPI_NUMA
1227
1228 config NUMA_EMU
1229 bool "NUMA emulation"
1230 depends on NUMA
1231 ---help---
1232 Enable NUMA emulation. A flat machine will be split
1233 into virtual nodes when booted with "numa=fake=N", where N is the
1234 number of nodes. This is only useful for debugging.
1235
1236 config NODES_SHIFT
1237 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1238 range 1 10
1239 default "10" if MAXSMP
1240 default "6" if X86_64
1241 default "3"
1242 depends on NEED_MULTIPLE_NODES
1243 ---help---
1244 Specify the maximum number of NUMA Nodes available on the target
1245 system. Increases memory reserved to accommodate various tables.
1246
1247 config ARCH_HAVE_MEMORY_PRESENT
1248 def_bool y
1249 depends on X86_32 && DISCONTIGMEM
1250
1251 config NEED_NODE_MEMMAP_SIZE
1252 def_bool y
1253 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1254
1255 config ARCH_FLATMEM_ENABLE
1256 def_bool y
1257 depends on X86_32 && !NUMA
1258
1259 config ARCH_DISCONTIGMEM_ENABLE
1260 def_bool y
1261 depends on NUMA && X86_32
1262
1263 config ARCH_DISCONTIGMEM_DEFAULT
1264 def_bool y
1265 depends on NUMA && X86_32
1266
1267 config ARCH_SPARSEMEM_ENABLE
1268 def_bool y
1269 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1270 select SPARSEMEM_STATIC if X86_32
1271 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1272
1273 config ARCH_SPARSEMEM_DEFAULT
1274 def_bool y
1275 depends on X86_64
1276
1277 config ARCH_SELECT_MEMORY_MODEL
1278 def_bool y
1279 depends on ARCH_SPARSEMEM_ENABLE
1280
1281 config ARCH_MEMORY_PROBE
1282 bool "Enable sysfs memory/probe interface"
1283 depends on X86_64 && MEMORY_HOTPLUG
1284 help
1285 This option enables a sysfs memory/probe interface for testing.
1286 See Documentation/memory-hotplug.txt for more information.
1287 If you are unsure how to answer this question, answer N.
1288
1289 config ARCH_PROC_KCORE_TEXT
1290 def_bool y
1291 depends on X86_64 && PROC_KCORE
1292
1293 config ILLEGAL_POINTER_VALUE
1294 hex
1295 default 0 if X86_32
1296 default 0xdead000000000000 if X86_64
1297
1298 source "mm/Kconfig"
1299
1300 config HIGHPTE
1301 bool "Allocate 3rd-level pagetables from highmem"
1302 depends on HIGHMEM
1303 ---help---
1304 The VM uses one page table entry for each page of physical memory.
1305 For systems with a lot of RAM, this can be wasteful of precious
1306 low memory. Setting this option will put user-space page table
1307 entries in high memory.
1308
1309 config X86_CHECK_BIOS_CORRUPTION
1310 bool "Check for low memory corruption"
1311 ---help---
1312 Periodically check for memory corruption in low memory, which
1313 is suspected to be caused by BIOS. Even when enabled in the
1314 configuration, it is disabled at runtime. Enable it by
1315 setting "memory_corruption_check=1" on the kernel command
1316 line. By default it scans the low 64k of memory every 60
1317 seconds; see the memory_corruption_check_size and
1318 memory_corruption_check_period parameters in
1319 Documentation/kernel-parameters.txt to adjust this.
1320
1321 When enabled with the default parameters, this option has
1322 almost no overhead, as it reserves a relatively small amount
1323 of memory and scans it infrequently. It both detects corruption
1324 and prevents it from affecting the running system.
1325
1326 It is, however, intended as a diagnostic tool; if repeatable
1327 BIOS-originated corruption always affects the same memory,
1328 you can use memmap= to prevent the kernel from using that
1329 memory.
1330
1331 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1332 bool "Set the default setting of memory_corruption_check"
1333 depends on X86_CHECK_BIOS_CORRUPTION
1334 default y
1335 ---help---
1336 Set whether the default state of memory_corruption_check is
1337 on or off.
1338
1339 config X86_RESERVE_LOW
1340 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1341 default 64
1342 range 4 640
1343 ---help---
1344 Specify the amount of low memory to reserve for the BIOS.
1345
1346 The first page contains BIOS data structures that the kernel
1347 must not use, so that page must always be reserved.
1348
1349 By default we reserve the first 64K of physical RAM, as a
1350 number of BIOSes are known to corrupt that memory range
1351 during events such as suspend/resume or monitor cable
1352 insertion, so it must not be used by the kernel.
1353
1354 You can set this to 4 if you are absolutely sure that you
1355 trust the BIOS to get all its memory reservations and usages
1356 right. If you know your BIOS have problems beyond the
1357 default 64K area, you can set this to 640 to avoid using the
1358 entire low memory range.
1359
1360 If you have doubts about the BIOS (e.g. suspend/resume does
1361 not work or there's kernel crashes after certain hardware
1362 hotplug events) then you might want to enable
1363 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1364 typical corruption patterns.
1365
1366 Leave this to the default value of 64 if you are unsure.
1367
1368 config MATH_EMULATION
1369 bool
1370 prompt "Math emulation" if X86_32
1371 ---help---
1372 Linux can emulate a math coprocessor (used for floating point
1373 operations) if you don't have one. 486DX and Pentium processors have
1374 a math coprocessor built in, 486SX and 386 do not, unless you added
1375 a 487DX or 387, respectively. (The messages during boot time can
1376 give you some hints here ["man dmesg"].) Everyone needs either a
1377 coprocessor or this emulation.
1378
1379 If you don't have a math coprocessor, you need to say Y here; if you
1380 say Y here even though you have a coprocessor, the coprocessor will
1381 be used nevertheless. (This behavior can be changed with the kernel
1382 command line option "no387", which comes handy if your coprocessor
1383 is broken. Try "man bootparam" or see the documentation of your boot
1384 loader (lilo or loadlin) about how to pass options to the kernel at
1385 boot time.) This means that it is a good idea to say Y here if you
1386 intend to use this kernel on different machines.
1387
1388 More information about the internals of the Linux math coprocessor
1389 emulation can be found in <file:arch/x86/math-emu/README>.
1390
1391 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1392 kernel, it won't hurt.
1393
1394 config MTRR
1395 def_bool y
1396 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1397 ---help---
1398 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1399 the Memory Type Range Registers (MTRRs) may be used to control
1400 processor access to memory ranges. This is most useful if you have
1401 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1402 allows bus write transfers to be combined into a larger transfer
1403 before bursting over the PCI/AGP bus. This can increase performance
1404 of image write operations 2.5 times or more. Saying Y here creates a
1405 /proc/mtrr file which may be used to manipulate your processor's
1406 MTRRs. Typically the X server should use this.
1407
1408 This code has a reasonably generic interface so that similar
1409 control registers on other processors can be easily supported
1410 as well:
1411
1412 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1413 Registers (ARRs) which provide a similar functionality to MTRRs. For
1414 these, the ARRs are used to emulate the MTRRs.
1415 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1416 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1417 write-combining. All of these processors are supported by this code
1418 and it makes sense to say Y here if you have one of them.
1419
1420 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1421 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1422 can lead to all sorts of problems, so it's good to say Y here.
1423
1424 You can safely say Y even if your machine doesn't have MTRRs, you'll
1425 just add about 9 KB to your kernel.
1426
1427 See <file:Documentation/x86/mtrr.txt> for more information.
1428
1429 config MTRR_SANITIZER
1430 def_bool y
1431 prompt "MTRR cleanup support"
1432 depends on MTRR
1433 ---help---
1434 Convert MTRR layout from continuous to discrete, so X drivers can
1435 add writeback entries.
1436
1437 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1438 The largest mtrr entry size for a continuous block can be set with
1439 mtrr_chunk_size.
1440
1441 If unsure, say Y.
1442
1443 config MTRR_SANITIZER_ENABLE_DEFAULT
1444 int "MTRR cleanup enable value (0-1)"
1445 range 0 1
1446 default "0"
1447 depends on MTRR_SANITIZER
1448 ---help---
1449 Enable mtrr cleanup default value
1450
1451 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1452 int "MTRR cleanup spare reg num (0-7)"
1453 range 0 7
1454 default "1"
1455 depends on MTRR_SANITIZER
1456 ---help---
1457 mtrr cleanup spare entries default, it can be changed via
1458 mtrr_spare_reg_nr=N on the kernel command line.
1459
1460 config X86_PAT
1461 def_bool y
1462 prompt "x86 PAT support" if EXPERT
1463 depends on MTRR
1464 ---help---
1465 Use PAT attributes to setup page level cache control.
1466
1467 PATs are the modern equivalents of MTRRs and are much more
1468 flexible than MTRRs.
1469
1470 Say N here if you see bootup problems (boot crash, boot hang,
1471 spontaneous reboots) or a non-working video driver.
1472
1473 If unsure, say Y.
1474
1475 config ARCH_USES_PG_UNCACHED
1476 def_bool y
1477 depends on X86_PAT
1478
1479 config ARCH_RANDOM
1480 def_bool y
1481 prompt "x86 architectural random number generator" if EXPERT
1482 ---help---
1483 Enable the x86 architectural RDRAND instruction
1484 (Intel Bull Mountain technology) to generate random numbers.
1485 If supported, this is a high bandwidth, cryptographically
1486 secure hardware random number generator.
1487
1488 config X86_SMAP
1489 def_bool y
1490 prompt "Supervisor Mode Access Prevention" if EXPERT
1491 ---help---
1492 Supervisor Mode Access Prevention (SMAP) is a security
1493 feature in newer Intel processors. There is a small
1494 performance cost if this enabled and turned on; there is
1495 also a small increase in the kernel size if this is enabled.
1496
1497 If unsure, say Y.
1498
1499 config EFI
1500 bool "EFI runtime service support"
1501 depends on ACPI
1502 select UCS2_STRING
1503 ---help---
1504 This enables the kernel to use EFI runtime services that are
1505 available (such as the EFI variable services).
1506
1507 This option is only useful on systems that have EFI firmware.
1508 In addition, you should use the latest ELILO loader available
1509 at <http://elilo.sourceforge.net> in order to take advantage
1510 of EFI runtime services. However, even with this option, the
1511 resultant kernel should continue to boot on existing non-EFI
1512 platforms.
1513
1514 config EFI_STUB
1515 bool "EFI stub support"
1516 depends on EFI
1517 ---help---
1518 This kernel feature allows a bzImage to be loaded directly
1519 by EFI firmware without the use of a bootloader.
1520
1521 See Documentation/efi-stub.txt for more information.
1522
1523 config EFI_MIXED
1524 bool "EFI mixed-mode support"
1525 depends on EFI_STUB && X86_64
1526 ---help---
1527 Enabling this feature allows a 64-bit kernel to be booted
1528 on a 32-bit firmware, provided that your CPU supports 64-bit
1529 mode.
1530
1531 Note that it is not possible to boot a mixed-mode enabled
1532 kernel via the EFI boot stub - a bootloader that supports
1533 the EFI handover protocol must be used.
1534
1535 If unsure, say N.
1536
1537 config SECCOMP
1538 def_bool y
1539 prompt "Enable seccomp to safely compute untrusted bytecode"
1540 ---help---
1541 This kernel feature is useful for number crunching applications
1542 that may need to compute untrusted bytecode during their
1543 execution. By using pipes or other transports made available to
1544 the process as file descriptors supporting the read/write
1545 syscalls, it's possible to isolate those applications in
1546 their own address space using seccomp. Once seccomp is
1547 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1548 and the task is only allowed to execute a few safe syscalls
1549 defined by each seccomp mode.
1550
1551 If unsure, say Y. Only embedded should say N here.
1552
1553 source kernel/Kconfig.hz
1554
1555 config KEXEC
1556 bool "kexec system call"
1557 ---help---
1558 kexec is a system call that implements the ability to shutdown your
1559 current kernel, and to start another kernel. It is like a reboot
1560 but it is independent of the system firmware. And like a reboot
1561 you can start any kernel with it, not just Linux.
1562
1563 The name comes from the similarity to the exec system call.
1564
1565 It is an ongoing process to be certain the hardware in a machine
1566 is properly shutdown, so do not be surprised if this code does not
1567 initially work for you. As of this writing the exact hardware
1568 interface is strongly in flux, so no good recommendation can be
1569 made.
1570
1571 config CRASH_DUMP
1572 bool "kernel crash dumps"
1573 depends on X86_64 || (X86_32 && HIGHMEM)
1574 ---help---
1575 Generate crash dump after being started by kexec.
1576 This should be normally only set in special crash dump kernels
1577 which are loaded in the main kernel with kexec-tools into
1578 a specially reserved region and then later executed after
1579 a crash by kdump/kexec. The crash dump kernel must be compiled
1580 to a memory address not used by the main kernel or BIOS using
1581 PHYSICAL_START, or it must be built as a relocatable image
1582 (CONFIG_RELOCATABLE=y).
1583 For more details see Documentation/kdump/kdump.txt
1584
1585 config KEXEC_JUMP
1586 bool "kexec jump"
1587 depends on KEXEC && HIBERNATION
1588 ---help---
1589 Jump between original kernel and kexeced kernel and invoke
1590 code in physical address mode via KEXEC
1591
1592 config PHYSICAL_START
1593 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1594 default "0x1000000"
1595 ---help---
1596 This gives the physical address where the kernel is loaded.
1597
1598 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1599 bzImage will decompress itself to above physical address and
1600 run from there. Otherwise, bzImage will run from the address where
1601 it has been loaded by the boot loader and will ignore above physical
1602 address.
1603
1604 In normal kdump cases one does not have to set/change this option
1605 as now bzImage can be compiled as a completely relocatable image
1606 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1607 address. This option is mainly useful for the folks who don't want
1608 to use a bzImage for capturing the crash dump and want to use a
1609 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1610 to be specifically compiled to run from a specific memory area
1611 (normally a reserved region) and this option comes handy.
1612
1613 So if you are using bzImage for capturing the crash dump,
1614 leave the value here unchanged to 0x1000000 and set
1615 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1616 for capturing the crash dump change this value to start of
1617 the reserved region. In other words, it can be set based on
1618 the "X" value as specified in the "crashkernel=YM@XM"
1619 command line boot parameter passed to the panic-ed
1620 kernel. Please take a look at Documentation/kdump/kdump.txt
1621 for more details about crash dumps.
1622
1623 Usage of bzImage for capturing the crash dump is recommended as
1624 one does not have to build two kernels. Same kernel can be used
1625 as production kernel and capture kernel. Above option should have
1626 gone away after relocatable bzImage support is introduced. But it
1627 is present because there are users out there who continue to use
1628 vmlinux for dump capture. This option should go away down the
1629 line.
1630
1631 Don't change this unless you know what you are doing.
1632
1633 config RELOCATABLE
1634 bool "Build a relocatable kernel"
1635 default y
1636 ---help---
1637 This builds a kernel image that retains relocation information
1638 so it can be loaded someplace besides the default 1MB.
1639 The relocations tend to make the kernel binary about 10% larger,
1640 but are discarded at runtime.
1641
1642 One use is for the kexec on panic case where the recovery kernel
1643 must live at a different physical address than the primary
1644 kernel.
1645
1646 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1647 it has been loaded at and the compile time physical address
1648 (CONFIG_PHYSICAL_START) is used as the minimum location.
1649
1650 config RANDOMIZE_BASE
1651 bool "Randomize the address of the kernel image"
1652 depends on RELOCATABLE
1653 depends on !HIBERNATION
1654 default n
1655 ---help---
1656 Randomizes the physical and virtual address at which the
1657 kernel image is decompressed, as a security feature that
1658 deters exploit attempts relying on knowledge of the location
1659 of kernel internals.
1660
1661 Entropy is generated using the RDRAND instruction if it is
1662 supported. If RDTSC is supported, it is used as well. If
1663 neither RDRAND nor RDTSC are supported, then randomness is
1664 read from the i8254 timer.
1665
1666 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1667 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1668 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1669 minimum of 2MiB, only 10 bits of entropy is theoretically
1670 possible. At best, due to page table layouts, 64-bit can use
1671 9 bits of entropy and 32-bit uses 8 bits.
1672
1673 If unsure, say N.
1674
1675 config RANDOMIZE_BASE_MAX_OFFSET
1676 hex "Maximum kASLR offset allowed" if EXPERT
1677 depends on RANDOMIZE_BASE
1678 range 0x0 0x20000000 if X86_32
1679 default "0x20000000" if X86_32
1680 range 0x0 0x40000000 if X86_64
1681 default "0x40000000" if X86_64
1682 ---help---
1683 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1684 memory is used to determine the maximal offset in bytes that will
1685 be applied to the kernel when kernel Address Space Layout
1686 Randomization (kASLR) is active. This must be a multiple of
1687 PHYSICAL_ALIGN.
1688
1689 On 32-bit this is limited to 512MiB by page table layouts. The
1690 default is 512MiB.
1691
1692 On 64-bit this is limited by how the kernel fixmap page table is
1693 positioned, so this cannot be larger than 1GiB currently. Without
1694 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1695 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1696 modules area will shrink to compensate, up to the current maximum
1697 1GiB to 1GiB split. The default is 1GiB.
1698
1699 If unsure, leave at the default value.
1700
1701 # Relocation on x86 needs some additional build support
1702 config X86_NEED_RELOCS
1703 def_bool y
1704 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1705
1706 config PHYSICAL_ALIGN
1707 hex "Alignment value to which kernel should be aligned"
1708 default "0x200000"
1709 range 0x2000 0x1000000 if X86_32
1710 range 0x200000 0x1000000 if X86_64
1711 ---help---
1712 This value puts the alignment restrictions on physical address
1713 where kernel is loaded and run from. Kernel is compiled for an
1714 address which meets above alignment restriction.
1715
1716 If bootloader loads the kernel at a non-aligned address and
1717 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1718 address aligned to above value and run from there.
1719
1720 If bootloader loads the kernel at a non-aligned address and
1721 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1722 load address and decompress itself to the address it has been
1723 compiled for and run from there. The address for which kernel is
1724 compiled already meets above alignment restrictions. Hence the
1725 end result is that kernel runs from a physical address meeting
1726 above alignment restrictions.
1727
1728 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1729 this value must be a multiple of 0x200000.
1730
1731 Don't change this unless you know what you are doing.
1732
1733 config HOTPLUG_CPU
1734 bool "Support for hot-pluggable CPUs"
1735 depends on SMP
1736 ---help---
1737 Say Y here to allow turning CPUs off and on. CPUs can be
1738 controlled through /sys/devices/system/cpu.
1739 ( Note: power management support will enable this option
1740 automatically on SMP systems. )
1741 Say N if you want to disable CPU hotplug.
1742
1743 config BOOTPARAM_HOTPLUG_CPU0
1744 bool "Set default setting of cpu0_hotpluggable"
1745 default n
1746 depends on HOTPLUG_CPU
1747 ---help---
1748 Set whether default state of cpu0_hotpluggable is on or off.
1749
1750 Say Y here to enable CPU0 hotplug by default. If this switch
1751 is turned on, there is no need to give cpu0_hotplug kernel
1752 parameter and the CPU0 hotplug feature is enabled by default.
1753
1754 Please note: there are two known CPU0 dependencies if you want
1755 to enable the CPU0 hotplug feature either by this switch or by
1756 cpu0_hotplug kernel parameter.
1757
1758 First, resume from hibernate or suspend always starts from CPU0.
1759 So hibernate and suspend are prevented if CPU0 is offline.
1760
1761 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1762 offline if any interrupt can not migrate out of CPU0. There may
1763 be other CPU0 dependencies.
1764
1765 Please make sure the dependencies are under your control before
1766 you enable this feature.
1767
1768 Say N if you don't want to enable CPU0 hotplug feature by default.
1769 You still can enable the CPU0 hotplug feature at boot by kernel
1770 parameter cpu0_hotplug.
1771
1772 config DEBUG_HOTPLUG_CPU0
1773 def_bool n
1774 prompt "Debug CPU0 hotplug"
1775 depends on HOTPLUG_CPU
1776 ---help---
1777 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1778 soon as possible and boots up userspace with CPU0 offlined. User
1779 can online CPU0 back after boot time.
1780
1781 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1782 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1783 compilation or giving cpu0_hotplug kernel parameter at boot.
1784
1785 If unsure, say N.
1786
1787 config COMPAT_VDSO
1788 def_bool n
1789 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1790 depends on X86_32 || IA32_EMULATION
1791 ---help---
1792 Certain buggy versions of glibc will crash if they are
1793 presented with a 32-bit vDSO that is not mapped at the address
1794 indicated in its segment table.
1795
1796 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1797 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1798 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1799 the only released version with the bug, but OpenSUSE 9
1800 contains a buggy "glibc 2.3.2".
1801
1802 The symptom of the bug is that everything crashes on startup, saying:
1803 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1804
1805 Saying Y here changes the default value of the vdso32 boot
1806 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1807 This works around the glibc bug but hurts performance.
1808
1809 If unsure, say N: if you are compiling your own kernel, you
1810 are unlikely to be using a buggy version of glibc.
1811
1812 config CMDLINE_BOOL
1813 bool "Built-in kernel command line"
1814 ---help---
1815 Allow for specifying boot arguments to the kernel at
1816 build time. On some systems (e.g. embedded ones), it is
1817 necessary or convenient to provide some or all of the
1818 kernel boot arguments with the kernel itself (that is,
1819 to not rely on the boot loader to provide them.)
1820
1821 To compile command line arguments into the kernel,
1822 set this option to 'Y', then fill in the
1823 the boot arguments in CONFIG_CMDLINE.
1824
1825 Systems with fully functional boot loaders (i.e. non-embedded)
1826 should leave this option set to 'N'.
1827
1828 config CMDLINE
1829 string "Built-in kernel command string"
1830 depends on CMDLINE_BOOL
1831 default ""
1832 ---help---
1833 Enter arguments here that should be compiled into the kernel
1834 image and used at boot time. If the boot loader provides a
1835 command line at boot time, it is appended to this string to
1836 form the full kernel command line, when the system boots.
1837
1838 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1839 change this behavior.
1840
1841 In most cases, the command line (whether built-in or provided
1842 by the boot loader) should specify the device for the root
1843 file system.
1844
1845 config CMDLINE_OVERRIDE
1846 bool "Built-in command line overrides boot loader arguments"
1847 depends on CMDLINE_BOOL
1848 ---help---
1849 Set this option to 'Y' to have the kernel ignore the boot loader
1850 command line, and use ONLY the built-in command line.
1851
1852 This is used to work around broken boot loaders. This should
1853 be set to 'N' under normal conditions.
1854
1855 endmenu
1856
1857 config ARCH_ENABLE_MEMORY_HOTPLUG
1858 def_bool y
1859 depends on X86_64 || (X86_32 && HIGHMEM)
1860
1861 config ARCH_ENABLE_MEMORY_HOTREMOVE
1862 def_bool y
1863 depends on MEMORY_HOTPLUG
1864
1865 config USE_PERCPU_NUMA_NODE_ID
1866 def_bool y
1867 depends on NUMA
1868
1869 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1870 def_bool y
1871 depends on X86_64 || X86_PAE
1872
1873 menu "Power management and ACPI options"
1874
1875 config ARCH_HIBERNATION_HEADER
1876 def_bool y
1877 depends on X86_64 && HIBERNATION
1878
1879 source "kernel/power/Kconfig"
1880
1881 source "drivers/acpi/Kconfig"
1882
1883 source "drivers/sfi/Kconfig"
1884
1885 config X86_APM_BOOT
1886 def_bool y
1887 depends on APM
1888
1889 menuconfig APM
1890 tristate "APM (Advanced Power Management) BIOS support"
1891 depends on X86_32 && PM_SLEEP
1892 ---help---
1893 APM is a BIOS specification for saving power using several different
1894 techniques. This is mostly useful for battery powered laptops with
1895 APM compliant BIOSes. If you say Y here, the system time will be
1896 reset after a RESUME operation, the /proc/apm device will provide
1897 battery status information, and user-space programs will receive
1898 notification of APM "events" (e.g. battery status change).
1899
1900 If you select "Y" here, you can disable actual use of the APM
1901 BIOS by passing the "apm=off" option to the kernel at boot time.
1902
1903 Note that the APM support is almost completely disabled for
1904 machines with more than one CPU.
1905
1906 In order to use APM, you will need supporting software. For location
1907 and more information, read <file:Documentation/power/apm-acpi.txt>
1908 and the Battery Powered Linux mini-HOWTO, available from
1909 <http://www.tldp.org/docs.html#howto>.
1910
1911 This driver does not spin down disk drives (see the hdparm(8)
1912 manpage ("man 8 hdparm") for that), and it doesn't turn off
1913 VESA-compliant "green" monitors.
1914
1915 This driver does not support the TI 4000M TravelMate and the ACER
1916 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1917 desktop machines also don't have compliant BIOSes, and this driver
1918 may cause those machines to panic during the boot phase.
1919
1920 Generally, if you don't have a battery in your machine, there isn't
1921 much point in using this driver and you should say N. If you get
1922 random kernel OOPSes or reboots that don't seem to be related to
1923 anything, try disabling/enabling this option (or disabling/enabling
1924 APM in your BIOS).
1925
1926 Some other things you should try when experiencing seemingly random,
1927 "weird" problems:
1928
1929 1) make sure that you have enough swap space and that it is
1930 enabled.
1931 2) pass the "no-hlt" option to the kernel
1932 3) switch on floating point emulation in the kernel and pass
1933 the "no387" option to the kernel
1934 4) pass the "floppy=nodma" option to the kernel
1935 5) pass the "mem=4M" option to the kernel (thereby disabling
1936 all but the first 4 MB of RAM)
1937 6) make sure that the CPU is not over clocked.
1938 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1939 8) disable the cache from your BIOS settings
1940 9) install a fan for the video card or exchange video RAM
1941 10) install a better fan for the CPU
1942 11) exchange RAM chips
1943 12) exchange the motherboard.
1944
1945 To compile this driver as a module, choose M here: the
1946 module will be called apm.
1947
1948 if APM
1949
1950 config APM_IGNORE_USER_SUSPEND
1951 bool "Ignore USER SUSPEND"
1952 ---help---
1953 This option will ignore USER SUSPEND requests. On machines with a
1954 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1955 series notebooks, it is necessary to say Y because of a BIOS bug.
1956
1957 config APM_DO_ENABLE
1958 bool "Enable PM at boot time"
1959 ---help---
1960 Enable APM features at boot time. From page 36 of the APM BIOS
1961 specification: "When disabled, the APM BIOS does not automatically
1962 power manage devices, enter the Standby State, enter the Suspend
1963 State, or take power saving steps in response to CPU Idle calls."
1964 This driver will make CPU Idle calls when Linux is idle (unless this
1965 feature is turned off -- see "Do CPU IDLE calls", below). This
1966 should always save battery power, but more complicated APM features
1967 will be dependent on your BIOS implementation. You may need to turn
1968 this option off if your computer hangs at boot time when using APM
1969 support, or if it beeps continuously instead of suspending. Turn
1970 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1971 T400CDT. This is off by default since most machines do fine without
1972 this feature.
1973
1974 config APM_CPU_IDLE
1975 depends on CPU_IDLE
1976 bool "Make CPU Idle calls when idle"
1977 ---help---
1978 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1979 On some machines, this can activate improved power savings, such as
1980 a slowed CPU clock rate, when the machine is idle. These idle calls
1981 are made after the idle loop has run for some length of time (e.g.,
1982 333 mS). On some machines, this will cause a hang at boot time or
1983 whenever the CPU becomes idle. (On machines with more than one CPU,
1984 this option does nothing.)
1985
1986 config APM_DISPLAY_BLANK
1987 bool "Enable console blanking using APM"
1988 ---help---
1989 Enable console blanking using the APM. Some laptops can use this to
1990 turn off the LCD backlight when the screen blanker of the Linux
1991 virtual console blanks the screen. Note that this is only used by
1992 the virtual console screen blanker, and won't turn off the backlight
1993 when using the X Window system. This also doesn't have anything to
1994 do with your VESA-compliant power-saving monitor. Further, this
1995 option doesn't work for all laptops -- it might not turn off your
1996 backlight at all, or it might print a lot of errors to the console,
1997 especially if you are using gpm.
1998
1999 config APM_ALLOW_INTS
2000 bool "Allow interrupts during APM BIOS calls"
2001 ---help---
2002 Normally we disable external interrupts while we are making calls to
2003 the APM BIOS as a measure to lessen the effects of a badly behaving
2004 BIOS implementation. The BIOS should reenable interrupts if it
2005 needs to. Unfortunately, some BIOSes do not -- especially those in
2006 many of the newer IBM Thinkpads. If you experience hangs when you
2007 suspend, try setting this to Y. Otherwise, say N.
2008
2009 endif # APM
2010
2011 source "drivers/cpufreq/Kconfig"
2012
2013 source "drivers/cpuidle/Kconfig"
2014
2015 source "drivers/idle/Kconfig"
2016
2017 endmenu
2018
2019
2020 menu "Bus options (PCI etc.)"
2021
2022 config PCI
2023 bool "PCI support"
2024 default y
2025 ---help---
2026 Find out whether you have a PCI motherboard. PCI is the name of a
2027 bus system, i.e. the way the CPU talks to the other stuff inside
2028 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2029 VESA. If you have PCI, say Y, otherwise N.
2030
2031 choice
2032 prompt "PCI access mode"
2033 depends on X86_32 && PCI
2034 default PCI_GOANY
2035 ---help---
2036 On PCI systems, the BIOS can be used to detect the PCI devices and
2037 determine their configuration. However, some old PCI motherboards
2038 have BIOS bugs and may crash if this is done. Also, some embedded
2039 PCI-based systems don't have any BIOS at all. Linux can also try to
2040 detect the PCI hardware directly without using the BIOS.
2041
2042 With this option, you can specify how Linux should detect the
2043 PCI devices. If you choose "BIOS", the BIOS will be used,
2044 if you choose "Direct", the BIOS won't be used, and if you
2045 choose "MMConfig", then PCI Express MMCONFIG will be used.
2046 If you choose "Any", the kernel will try MMCONFIG, then the
2047 direct access method and falls back to the BIOS if that doesn't
2048 work. If unsure, go with the default, which is "Any".
2049
2050 config PCI_GOBIOS
2051 bool "BIOS"
2052
2053 config PCI_GOMMCONFIG
2054 bool "MMConfig"
2055
2056 config PCI_GODIRECT
2057 bool "Direct"
2058
2059 config PCI_GOOLPC
2060 bool "OLPC XO-1"
2061 depends on OLPC
2062
2063 config PCI_GOANY
2064 bool "Any"
2065
2066 endchoice
2067
2068 config PCI_BIOS
2069 def_bool y
2070 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2071
2072 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2073 config PCI_DIRECT
2074 def_bool y
2075 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2076
2077 config PCI_MMCONFIG
2078 def_bool y
2079 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2080
2081 config PCI_OLPC
2082 def_bool y
2083 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2084
2085 config PCI_XEN
2086 def_bool y
2087 depends on PCI && XEN
2088 select SWIOTLB_XEN
2089
2090 config PCI_DOMAINS
2091 def_bool y
2092 depends on PCI
2093
2094 config PCI_MMCONFIG
2095 bool "Support mmconfig PCI config space access"
2096 depends on X86_64 && PCI && ACPI
2097
2098 config PCI_CNB20LE_QUIRK
2099 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2100 depends on PCI
2101 help
2102 Read the PCI windows out of the CNB20LE host bridge. This allows
2103 PCI hotplug to work on systems with the CNB20LE chipset which do
2104 not have ACPI.
2105
2106 There's no public spec for this chipset, and this functionality
2107 is known to be incomplete.
2108
2109 You should say N unless you know you need this.
2110
2111 source "drivers/pci/pcie/Kconfig"
2112
2113 source "drivers/pci/Kconfig"
2114
2115 # x86_64 have no ISA slots, but can have ISA-style DMA.
2116 config ISA_DMA_API
2117 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2118 default y
2119 help
2120 Enables ISA-style DMA support for devices requiring such controllers.
2121 If unsure, say Y.
2122
2123 if X86_32
2124
2125 config ISA
2126 bool "ISA support"
2127 ---help---
2128 Find out whether you have ISA slots on your motherboard. ISA is the
2129 name of a bus system, i.e. the way the CPU talks to the other stuff
2130 inside your box. Other bus systems are PCI, EISA, MicroChannel
2131 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2132 newer boards don't support it. If you have ISA, say Y, otherwise N.
2133
2134 config EISA
2135 bool "EISA support"
2136 depends on ISA
2137 ---help---
2138 The Extended Industry Standard Architecture (EISA) bus was
2139 developed as an open alternative to the IBM MicroChannel bus.
2140
2141 The EISA bus provided some of the features of the IBM MicroChannel
2142 bus while maintaining backward compatibility with cards made for
2143 the older ISA bus. The EISA bus saw limited use between 1988 and
2144 1995 when it was made obsolete by the PCI bus.
2145
2146 Say Y here if you are building a kernel for an EISA-based machine.
2147
2148 Otherwise, say N.
2149
2150 source "drivers/eisa/Kconfig"
2151
2152 config SCx200
2153 tristate "NatSemi SCx200 support"
2154 ---help---
2155 This provides basic support for National Semiconductor's
2156 (now AMD's) Geode processors. The driver probes for the
2157 PCI-IDs of several on-chip devices, so its a good dependency
2158 for other scx200_* drivers.
2159
2160 If compiled as a module, the driver is named scx200.
2161
2162 config SCx200HR_TIMER
2163 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2164 depends on SCx200
2165 default y
2166 ---help---
2167 This driver provides a clocksource built upon the on-chip
2168 27MHz high-resolution timer. Its also a workaround for
2169 NSC Geode SC-1100's buggy TSC, which loses time when the
2170 processor goes idle (as is done by the scheduler). The
2171 other workaround is idle=poll boot option.
2172
2173 config OLPC
2174 bool "One Laptop Per Child support"
2175 depends on !X86_PAE
2176 select GPIOLIB
2177 select OF
2178 select OF_PROMTREE
2179 select IRQ_DOMAIN
2180 ---help---
2181 Add support for detecting the unique features of the OLPC
2182 XO hardware.
2183
2184 config OLPC_XO1_PM
2185 bool "OLPC XO-1 Power Management"
2186 depends on OLPC && MFD_CS5535 && PM_SLEEP
2187 select MFD_CORE
2188 ---help---
2189 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2190
2191 config OLPC_XO1_RTC
2192 bool "OLPC XO-1 Real Time Clock"
2193 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2194 ---help---
2195 Add support for the XO-1 real time clock, which can be used as a
2196 programmable wakeup source.
2197
2198 config OLPC_XO1_SCI
2199 bool "OLPC XO-1 SCI extras"
2200 depends on OLPC && OLPC_XO1_PM
2201 depends on INPUT=y
2202 select POWER_SUPPLY
2203 select GPIO_CS5535
2204 select MFD_CORE
2205 ---help---
2206 Add support for SCI-based features of the OLPC XO-1 laptop:
2207 - EC-driven system wakeups
2208 - Power button
2209 - Ebook switch
2210 - Lid switch
2211 - AC adapter status updates
2212 - Battery status updates
2213
2214 config OLPC_XO15_SCI
2215 bool "OLPC XO-1.5 SCI extras"
2216 depends on OLPC && ACPI
2217 select POWER_SUPPLY
2218 ---help---
2219 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2220 - EC-driven system wakeups
2221 - AC adapter status updates
2222 - Battery status updates
2223
2224 config ALIX
2225 bool "PCEngines ALIX System Support (LED setup)"
2226 select GPIOLIB
2227 ---help---
2228 This option enables system support for the PCEngines ALIX.
2229 At present this just sets up LEDs for GPIO control on
2230 ALIX2/3/6 boards. However, other system specific setup should
2231 get added here.
2232
2233 Note: You must still enable the drivers for GPIO and LED support
2234 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2235
2236 Note: You have to set alix.force=1 for boards with Award BIOS.
2237
2238 config NET5501
2239 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2240 select GPIOLIB
2241 ---help---
2242 This option enables system support for the Soekris Engineering net5501.
2243
2244 config GEOS
2245 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2246 select GPIOLIB
2247 depends on DMI
2248 ---help---
2249 This option enables system support for the Traverse Technologies GEOS.
2250
2251 config TS5500
2252 bool "Technologic Systems TS-5500 platform support"
2253 depends on MELAN
2254 select CHECK_SIGNATURE
2255 select NEW_LEDS
2256 select LEDS_CLASS
2257 ---help---
2258 This option enables system support for the Technologic Systems TS-5500.
2259
2260 endif # X86_32
2261
2262 config AMD_NB
2263 def_bool y
2264 depends on CPU_SUP_AMD && PCI
2265
2266 source "drivers/pcmcia/Kconfig"
2267
2268 source "drivers/pci/hotplug/Kconfig"
2269
2270 config RAPIDIO
2271 tristate "RapidIO support"
2272 depends on PCI
2273 default n
2274 help
2275 If enabled this option will include drivers and the core
2276 infrastructure code to support RapidIO interconnect devices.
2277
2278 source "drivers/rapidio/Kconfig"
2279
2280 config X86_SYSFB
2281 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2282 help
2283 Firmwares often provide initial graphics framebuffers so the BIOS,
2284 bootloader or kernel can show basic video-output during boot for
2285 user-guidance and debugging. Historically, x86 used the VESA BIOS
2286 Extensions and EFI-framebuffers for this, which are mostly limited
2287 to x86.
2288 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2289 framebuffers so the new generic system-framebuffer drivers can be
2290 used on x86. If the framebuffer is not compatible with the generic
2291 modes, it is adverticed as fallback platform framebuffer so legacy
2292 drivers like efifb, vesafb and uvesafb can pick it up.
2293 If this option is not selected, all system framebuffers are always
2294 marked as fallback platform framebuffers as usual.
2295
2296 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2297 not be able to pick up generic system framebuffers if this option
2298 is selected. You are highly encouraged to enable simplefb as
2299 replacement if you select this option. simplefb can correctly deal
2300 with generic system framebuffers. But you should still keep vesafb
2301 and others enabled as fallback if a system framebuffer is
2302 incompatible with simplefb.
2303
2304 If unsure, say Y.
2305
2306 endmenu
2307
2308
2309 menu "Executable file formats / Emulations"
2310
2311 source "fs/Kconfig.binfmt"
2312
2313 config IA32_EMULATION
2314 bool "IA32 Emulation"
2315 depends on X86_64
2316 select BINFMT_ELF
2317 select COMPAT_BINFMT_ELF
2318 select HAVE_UID16
2319 ---help---
2320 Include code to run legacy 32-bit programs under a
2321 64-bit kernel. You should likely turn this on, unless you're
2322 100% sure that you don't have any 32-bit programs left.
2323
2324 config IA32_AOUT
2325 tristate "IA32 a.out support"
2326 depends on IA32_EMULATION
2327 ---help---
2328 Support old a.out binaries in the 32bit emulation.
2329
2330 config X86_X32
2331 bool "x32 ABI for 64-bit mode"
2332 depends on X86_64 && IA32_EMULATION
2333 ---help---
2334 Include code to run binaries for the x32 native 32-bit ABI
2335 for 64-bit processors. An x32 process gets access to the
2336 full 64-bit register file and wide data path while leaving
2337 pointers at 32 bits for smaller memory footprint.
2338
2339 You will need a recent binutils (2.22 or later) with
2340 elf32_x86_64 support enabled to compile a kernel with this
2341 option set.
2342
2343 config COMPAT
2344 def_bool y
2345 depends on IA32_EMULATION || X86_X32
2346 select ARCH_WANT_OLD_COMPAT_IPC
2347
2348 if COMPAT
2349 config COMPAT_FOR_U64_ALIGNMENT
2350 def_bool y
2351
2352 config SYSVIPC_COMPAT
2353 def_bool y
2354 depends on SYSVIPC
2355
2356 config KEYS_COMPAT
2357 def_bool y
2358 depends on KEYS
2359 endif
2360
2361 endmenu
2362
2363
2364 config HAVE_ATOMIC_IOMAP
2365 def_bool y
2366 depends on X86_32
2367
2368 config X86_DEV_DMA_OPS
2369 bool
2370 depends on X86_64 || STA2X11
2371
2372 config X86_DMA_REMAP
2373 bool
2374 depends on STA2X11
2375
2376 config IOSF_MBI
2377 bool
2378 depends on PCI
2379 ---help---
2380 To be selected by modules requiring access to the Intel OnChip System
2381 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2382 enumerable by PCI.
2383
2384 source "net/Kconfig"
2385
2386 source "drivers/Kconfig"
2387
2388 source "drivers/firmware/Kconfig"
2389
2390 source "fs/Kconfig"
2391
2392 source "arch/x86/Kconfig.debug"
2393
2394 source "security/Kconfig"
2395
2396 source "crypto/Kconfig"
2397
2398 source "arch/x86/kvm/Kconfig"
2399
2400 source "lib/Kconfig"
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