Merge 3.15-rc3 into tty-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 config FIX_EARLYCON_MEM
265 def_bool y
266
267 source "init/Kconfig"
268 source "kernel/Kconfig.freezer"
269
270 menu "Processor type and features"
271
272 config ZONE_DMA
273 bool "DMA memory allocation support" if EXPERT
274 default y
275 help
276 DMA memory allocation support allows devices with less than 32-bit
277 addressing to allocate within the first 16MB of address space.
278 Disable if no such devices will be used.
279
280 If unsure, say Y.
281
282 config SMP
283 bool "Symmetric multi-processing support"
284 ---help---
285 This enables support for systems with more than one CPU. If you have
286 a system with only one CPU, say N. If you have a system with more
287 than one CPU, say Y.
288
289 If you say N here, the kernel will run on uni- and multiprocessor
290 machines, but will use only one CPU of a multiprocessor machine. If
291 you say Y here, the kernel will run on many, but not all,
292 uniprocessor machines. On a uniprocessor machine, the kernel
293 will run faster if you say N here.
294
295 Note that if you say Y here and choose architecture "586" or
296 "Pentium" under "Processor family", the kernel will not work on 486
297 architectures. Similarly, multiprocessor kernels for the "PPro"
298 architecture may not work on all Pentium based boards.
299
300 People using multiprocessor machines who say Y here should also say
301 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
302 Management" code will be disabled if you say Y here.
303
304 See also <file:Documentation/x86/i386/IO-APIC.txt>,
305 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
306 <http://www.tldp.org/docs.html#howto>.
307
308 If you don't know what to do here, say N.
309
310 config X86_X2APIC
311 bool "Support x2apic"
312 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
313 ---help---
314 This enables x2apic support on CPUs that have this feature.
315
316 This allows 32-bit apic IDs (so it can support very large systems),
317 and accesses the local apic via MSRs not via mmio.
318
319 If you don't know what to do here, say N.
320
321 config X86_MPPARSE
322 bool "Enable MPS table" if ACPI || SFI
323 default y
324 depends on X86_LOCAL_APIC
325 ---help---
326 For old smp systems that do not have proper acpi support. Newer systems
327 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
328
329 config X86_BIGSMP
330 bool "Support for big SMP systems with more than 8 CPUs"
331 depends on X86_32 && SMP
332 ---help---
333 This option is needed for the systems that have more than 8 CPUs
334
335 config GOLDFISH
336 def_bool y
337 depends on X86_GOLDFISH
338
339 if X86_32
340 config X86_EXTENDED_PLATFORM
341 bool "Support for extended (non-PC) x86 platforms"
342 default y
343 ---help---
344 If you disable this option then the kernel will only support
345 standard PC platforms. (which covers the vast majority of
346 systems out there.)
347
348 If you enable this option then you'll be able to select support
349 for the following (non-PC) 32 bit x86 platforms:
350 Goldfish (Android emulator)
351 AMD Elan
352 RDC R-321x SoC
353 SGI 320/540 (Visual Workstation)
354 STA2X11-based (e.g. Northville)
355 Moorestown MID devices
356
357 If you have one of these systems, or if you want to build a
358 generic distribution kernel, say Y here - otherwise say N.
359 endif
360
361 if X86_64
362 config X86_EXTENDED_PLATFORM
363 bool "Support for extended (non-PC) x86 platforms"
364 default y
365 ---help---
366 If you disable this option then the kernel will only support
367 standard PC platforms. (which covers the vast majority of
368 systems out there.)
369
370 If you enable this option then you'll be able to select support
371 for the following (non-PC) 64 bit x86 platforms:
372 Numascale NumaChip
373 ScaleMP vSMP
374 SGI Ultraviolet
375
376 If you have one of these systems, or if you want to build a
377 generic distribution kernel, say Y here - otherwise say N.
378 endif
379 # This is an alphabetically sorted list of 64 bit extended platforms
380 # Please maintain the alphabetic order if and when there are additions
381 config X86_NUMACHIP
382 bool "Numascale NumaChip"
383 depends on X86_64
384 depends on X86_EXTENDED_PLATFORM
385 depends on NUMA
386 depends on SMP
387 depends on X86_X2APIC
388 depends on PCI_MMCONFIG
389 ---help---
390 Adds support for Numascale NumaChip large-SMP systems. Needed to
391 enable more than ~168 cores.
392 If you don't have one of these, you should say N here.
393
394 config X86_VSMP
395 bool "ScaleMP vSMP"
396 select HYPERVISOR_GUEST
397 select PARAVIRT
398 depends on X86_64 && PCI
399 depends on X86_EXTENDED_PLATFORM
400 depends on SMP
401 ---help---
402 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
403 supposed to run on these EM64T-based machines. Only choose this option
404 if you have one of these machines.
405
406 config X86_UV
407 bool "SGI Ultraviolet"
408 depends on X86_64
409 depends on X86_EXTENDED_PLATFORM
410 depends on NUMA
411 depends on X86_X2APIC
412 ---help---
413 This option is needed in order to support SGI Ultraviolet systems.
414 If you don't have one of these, you should say N here.
415
416 # Following is an alphabetically sorted list of 32 bit extended platforms
417 # Please maintain the alphabetic order if and when there are additions
418
419 config X86_GOLDFISH
420 bool "Goldfish (Virtual Platform)"
421 depends on X86_32
422 depends on X86_EXTENDED_PLATFORM
423 ---help---
424 Enable support for the Goldfish virtual platform used primarily
425 for Android development. Unless you are building for the Android
426 Goldfish emulator say N here.
427
428 config X86_INTEL_CE
429 bool "CE4100 TV platform"
430 depends on PCI
431 depends on PCI_GODIRECT
432 depends on X86_32
433 depends on X86_EXTENDED_PLATFORM
434 select X86_REBOOTFIXUPS
435 select OF
436 select OF_EARLY_FLATTREE
437 select IRQ_DOMAIN
438 ---help---
439 Select for the Intel CE media processor (CE4100) SOC.
440 This option compiles in support for the CE4100 SOC for settop
441 boxes and media devices.
442
443 config X86_INTEL_MID
444 bool "Intel MID platform support"
445 depends on X86_32
446 depends on X86_EXTENDED_PLATFORM
447 depends on X86_PLATFORM_DEVICES
448 depends on PCI
449 depends on PCI_GOANY
450 depends on X86_IO_APIC
451 select SFI
452 select I2C
453 select DW_APB_TIMER
454 select APB_TIMER
455 select INTEL_SCU_IPC
456 select MFD_INTEL_MSIC
457 ---help---
458 Select to build a kernel capable of supporting Intel MID (Mobile
459 Internet Device) platform systems which do not have the PCI legacy
460 interfaces. If you are building for a PC class system say N here.
461
462 Intel MID platforms are based on an Intel processor and chipset which
463 consume less power than most of the x86 derivatives.
464
465 config X86_INTEL_LPSS
466 bool "Intel Low Power Subsystem Support"
467 depends on ACPI
468 select COMMON_CLK
469 select PINCTRL
470 ---help---
471 Select to build support for Intel Low Power Subsystem such as
472 found on Intel Lynxpoint PCH. Selecting this option enables
473 things like clock tree (common clock framework) and pincontrol
474 which are needed by the LPSS peripheral drivers.
475
476 config X86_RDC321X
477 bool "RDC R-321x SoC"
478 depends on X86_32
479 depends on X86_EXTENDED_PLATFORM
480 select M486
481 select X86_REBOOTFIXUPS
482 ---help---
483 This option is needed for RDC R-321x system-on-chip, also known
484 as R-8610-(G).
485 If you don't have one of these chips, you should say N here.
486
487 config X86_32_NON_STANDARD
488 bool "Support non-standard 32-bit SMP architectures"
489 depends on X86_32 && SMP
490 depends on X86_EXTENDED_PLATFORM
491 ---help---
492 This option compiles in the bigsmp and STA2X11 default
493 subarchitectures. It is intended for a generic binary
494 kernel. If you select them all, kernel will probe it one by
495 one and will fallback to default.
496
497 # Alphabetically sorted list of Non standard 32 bit platforms
498
499 config X86_SUPPORTS_MEMORY_FAILURE
500 def_bool y
501 # MCE code calls memory_failure():
502 depends on X86_MCE
503 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
504 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
505 depends on X86_64 || !SPARSEMEM
506 select ARCH_SUPPORTS_MEMORY_FAILURE
507
508 config STA2X11
509 bool "STA2X11 Companion Chip Support"
510 depends on X86_32_NON_STANDARD && PCI
511 select X86_DEV_DMA_OPS
512 select X86_DMA_REMAP
513 select SWIOTLB
514 select MFD_STA2X11
515 select ARCH_REQUIRE_GPIOLIB
516 default n
517 ---help---
518 This adds support for boards based on the STA2X11 IO-Hub,
519 a.k.a. "ConneXt". The chip is used in place of the standard
520 PC chipset, so all "standard" peripherals are missing. If this
521 option is selected the kernel will still be able to boot on
522 standard PC machines.
523
524 config X86_32_IRIS
525 tristate "Eurobraille/Iris poweroff module"
526 depends on X86_32
527 ---help---
528 The Iris machines from EuroBraille do not have APM or ACPI support
529 to shut themselves down properly. A special I/O sequence is
530 needed to do so, which is what this module does at
531 kernel shutdown.
532
533 This is only for Iris machines from EuroBraille.
534
535 If unused, say N.
536
537 config SCHED_OMIT_FRAME_POINTER
538 def_bool y
539 prompt "Single-depth WCHAN output"
540 depends on X86
541 ---help---
542 Calculate simpler /proc/<PID>/wchan values. If this option
543 is disabled then wchan values will recurse back to the
544 caller function. This provides more accurate wchan values,
545 at the expense of slightly more scheduling overhead.
546
547 If in doubt, say "Y".
548
549 menuconfig HYPERVISOR_GUEST
550 bool "Linux guest support"
551 ---help---
552 Say Y here to enable options for running Linux under various hyper-
553 visors. This option enables basic hypervisor detection and platform
554 setup.
555
556 If you say N, all options in this submenu will be skipped and
557 disabled, and Linux guest support won't be built in.
558
559 if HYPERVISOR_GUEST
560
561 config PARAVIRT
562 bool "Enable paravirtualization code"
563 ---help---
564 This changes the kernel so it can modify itself when it is run
565 under a hypervisor, potentially improving performance significantly
566 over full virtualization. However, when run without a hypervisor
567 the kernel is theoretically slower and slightly larger.
568
569 config PARAVIRT_DEBUG
570 bool "paravirt-ops debugging"
571 depends on PARAVIRT && DEBUG_KERNEL
572 ---help---
573 Enable to debug paravirt_ops internals. Specifically, BUG if
574 a paravirt_op is missing when it is called.
575
576 config PARAVIRT_SPINLOCKS
577 bool "Paravirtualization layer for spinlocks"
578 depends on PARAVIRT && SMP
579 select UNINLINE_SPIN_UNLOCK
580 ---help---
581 Paravirtualized spinlocks allow a pvops backend to replace the
582 spinlock implementation with something virtualization-friendly
583 (for example, block the virtual CPU rather than spinning).
584
585 It has a minimal impact on native kernels and gives a nice performance
586 benefit on paravirtualized KVM / Xen kernels.
587
588 If you are unsure how to answer this question, answer Y.
589
590 source "arch/x86/xen/Kconfig"
591
592 config KVM_GUEST
593 bool "KVM Guest support (including kvmclock)"
594 depends on PARAVIRT
595 select PARAVIRT_CLOCK
596 default y
597 ---help---
598 This option enables various optimizations for running under the KVM
599 hypervisor. It includes a paravirtualized clock, so that instead
600 of relying on a PIT (or probably other) emulation by the
601 underlying device model, the host provides the guest with
602 timing infrastructure such as time of day, and system time
603
604 config KVM_DEBUG_FS
605 bool "Enable debug information for KVM Guests in debugfs"
606 depends on KVM_GUEST && DEBUG_FS
607 default n
608 ---help---
609 This option enables collection of various statistics for KVM guest.
610 Statistics are displayed in debugfs filesystem. Enabling this option
611 may incur significant overhead.
612
613 source "arch/x86/lguest/Kconfig"
614
615 config PARAVIRT_TIME_ACCOUNTING
616 bool "Paravirtual steal time accounting"
617 depends on PARAVIRT
618 default n
619 ---help---
620 Select this option to enable fine granularity task steal time
621 accounting. Time spent executing other tasks in parallel with
622 the current vCPU is discounted from the vCPU power. To account for
623 that, there can be a small performance impact.
624
625 If in doubt, say N here.
626
627 config PARAVIRT_CLOCK
628 bool
629
630 endif #HYPERVISOR_GUEST
631
632 config NO_BOOTMEM
633 def_bool y
634
635 config MEMTEST
636 bool "Memtest"
637 ---help---
638 This option adds a kernel parameter 'memtest', which allows memtest
639 to be set.
640 memtest=0, mean disabled; -- default
641 memtest=1, mean do 1 test pattern;
642 ...
643 memtest=4, mean do 4 test patterns.
644 If you are unsure how to answer this question, answer N.
645
646 source "arch/x86/Kconfig.cpu"
647
648 config HPET_TIMER
649 def_bool X86_64
650 prompt "HPET Timer Support" if X86_32
651 ---help---
652 Use the IA-PC HPET (High Precision Event Timer) to manage
653 time in preference to the PIT and RTC, if a HPET is
654 present.
655 HPET is the next generation timer replacing legacy 8254s.
656 The HPET provides a stable time base on SMP
657 systems, unlike the TSC, but it is more expensive to access,
658 as it is off-chip. You can find the HPET spec at
659 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
660
661 You can safely choose Y here. However, HPET will only be
662 activated if the platform and the BIOS support this feature.
663 Otherwise the 8254 will be used for timing services.
664
665 Choose N to continue using the legacy 8254 timer.
666
667 config HPET_EMULATE_RTC
668 def_bool y
669 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
670
671 config APB_TIMER
672 def_bool y if X86_INTEL_MID
673 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
674 select DW_APB_TIMER
675 depends on X86_INTEL_MID && SFI
676 help
677 APB timer is the replacement for 8254, HPET on X86 MID platforms.
678 The APBT provides a stable time base on SMP
679 systems, unlike the TSC, but it is more expensive to access,
680 as it is off-chip. APB timers are always running regardless of CPU
681 C states, they are used as per CPU clockevent device when possible.
682
683 # Mark as expert because too many people got it wrong.
684 # The code disables itself when not needed.
685 config DMI
686 default y
687 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
688 bool "Enable DMI scanning" if EXPERT
689 ---help---
690 Enabled scanning of DMI to identify machine quirks. Say Y
691 here unless you have verified that your setup is not
692 affected by entries in the DMI blacklist. Required by PNP
693 BIOS code.
694
695 config GART_IOMMU
696 bool "Old AMD GART IOMMU support"
697 select SWIOTLB
698 depends on X86_64 && PCI && AMD_NB
699 ---help---
700 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
701 GART based hardware IOMMUs.
702
703 The GART supports full DMA access for devices with 32-bit access
704 limitations, on systems with more than 3 GB. This is usually needed
705 for USB, sound, many IDE/SATA chipsets and some other devices.
706
707 Newer systems typically have a modern AMD IOMMU, supported via
708 the CONFIG_AMD_IOMMU=y config option.
709
710 In normal configurations this driver is only active when needed:
711 there's more than 3 GB of memory and the system contains a
712 32-bit limited device.
713
714 If unsure, say Y.
715
716 config CALGARY_IOMMU
717 bool "IBM Calgary IOMMU support"
718 select SWIOTLB
719 depends on X86_64 && PCI
720 ---help---
721 Support for hardware IOMMUs in IBM's xSeries x366 and x460
722 systems. Needed to run systems with more than 3GB of memory
723 properly with 32-bit PCI devices that do not support DAC
724 (Double Address Cycle). Calgary also supports bus level
725 isolation, where all DMAs pass through the IOMMU. This
726 prevents them from going anywhere except their intended
727 destination. This catches hard-to-find kernel bugs and
728 mis-behaving drivers and devices that do not use the DMA-API
729 properly to set up their DMA buffers. The IOMMU can be
730 turned off at boot time with the iommu=off parameter.
731 Normally the kernel will make the right choice by itself.
732 If unsure, say Y.
733
734 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
735 def_bool y
736 prompt "Should Calgary be enabled by default?"
737 depends on CALGARY_IOMMU
738 ---help---
739 Should Calgary be enabled by default? if you choose 'y', Calgary
740 will be used (if it exists). If you choose 'n', Calgary will not be
741 used even if it exists. If you choose 'n' and would like to use
742 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
743 If unsure, say Y.
744
745 # need this always selected by IOMMU for the VIA workaround
746 config SWIOTLB
747 def_bool y if X86_64
748 ---help---
749 Support for software bounce buffers used on x86-64 systems
750 which don't have a hardware IOMMU. Using this PCI devices
751 which can only access 32-bits of memory can be used on systems
752 with more than 3 GB of memory.
753 If unsure, say Y.
754
755 config IOMMU_HELPER
756 def_bool y
757 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
758
759 config MAXSMP
760 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
761 depends on X86_64 && SMP && DEBUG_KERNEL
762 select CPUMASK_OFFSTACK
763 ---help---
764 Enable maximum number of CPUS and NUMA Nodes for this architecture.
765 If unsure, say N.
766
767 config NR_CPUS
768 int "Maximum number of CPUs" if SMP && !MAXSMP
769 range 2 8 if SMP && X86_32 && !X86_BIGSMP
770 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
771 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
772 default "1" if !SMP
773 default "8192" if MAXSMP
774 default "32" if SMP && X86_BIGSMP
775 default "8" if SMP
776 ---help---
777 This allows you to specify the maximum number of CPUs which this
778 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
779 supported value is 4096, otherwise the maximum value is 512. The
780 minimum value which makes sense is 2.
781
782 This is purely to save memory - each supported CPU adds
783 approximately eight kilobytes to the kernel image.
784
785 config SCHED_SMT
786 bool "SMT (Hyperthreading) scheduler support"
787 depends on X86_HT
788 ---help---
789 SMT scheduler support improves the CPU scheduler's decision making
790 when dealing with Intel Pentium 4 chips with HyperThreading at a
791 cost of slightly increased overhead in some places. If unsure say
792 N here.
793
794 config SCHED_MC
795 def_bool y
796 prompt "Multi-core scheduler support"
797 depends on X86_HT
798 ---help---
799 Multi-core scheduler support improves the CPU scheduler's decision
800 making when dealing with multi-core CPU chips at a cost of slightly
801 increased overhead in some places. If unsure say N here.
802
803 source "kernel/Kconfig.preempt"
804
805 config X86_UP_APIC
806 bool "Local APIC support on uniprocessors"
807 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
808 ---help---
809 A local APIC (Advanced Programmable Interrupt Controller) is an
810 integrated interrupt controller in the CPU. If you have a single-CPU
811 system which has a processor with a local APIC, you can say Y here to
812 enable and use it. If you say Y here even though your machine doesn't
813 have a local APIC, then the kernel will still run with no slowdown at
814 all. The local APIC supports CPU-generated self-interrupts (timer,
815 performance counters), and the NMI watchdog which detects hard
816 lockups.
817
818 config X86_UP_IOAPIC
819 bool "IO-APIC support on uniprocessors"
820 depends on X86_UP_APIC
821 ---help---
822 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
823 SMP-capable replacement for PC-style interrupt controllers. Most
824 SMP systems and many recent uniprocessor systems have one.
825
826 If you have a single-CPU system with an IO-APIC, you can say Y here
827 to use it. If you say Y here even though your machine doesn't have
828 an IO-APIC, then the kernel will still run with no slowdown at all.
829
830 config X86_LOCAL_APIC
831 def_bool y
832 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
833
834 config X86_IO_APIC
835 def_bool y
836 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
837
838 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
839 bool "Reroute for broken boot IRQs"
840 depends on X86_IO_APIC
841 ---help---
842 This option enables a workaround that fixes a source of
843 spurious interrupts. This is recommended when threaded
844 interrupt handling is used on systems where the generation of
845 superfluous "boot interrupts" cannot be disabled.
846
847 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
848 entry in the chipset's IO-APIC is masked (as, e.g. the RT
849 kernel does during interrupt handling). On chipsets where this
850 boot IRQ generation cannot be disabled, this workaround keeps
851 the original IRQ line masked so that only the equivalent "boot
852 IRQ" is delivered to the CPUs. The workaround also tells the
853 kernel to set up the IRQ handler on the boot IRQ line. In this
854 way only one interrupt is delivered to the kernel. Otherwise
855 the spurious second interrupt may cause the kernel to bring
856 down (vital) interrupt lines.
857
858 Only affects "broken" chipsets. Interrupt sharing may be
859 increased on these systems.
860
861 config X86_MCE
862 bool "Machine Check / overheating reporting"
863 default y
864 ---help---
865 Machine Check support allows the processor to notify the
866 kernel if it detects a problem (e.g. overheating, data corruption).
867 The action the kernel takes depends on the severity of the problem,
868 ranging from warning messages to halting the machine.
869
870 config X86_MCE_INTEL
871 def_bool y
872 prompt "Intel MCE features"
873 depends on X86_MCE && X86_LOCAL_APIC
874 ---help---
875 Additional support for intel specific MCE features such as
876 the thermal monitor.
877
878 config X86_MCE_AMD
879 def_bool y
880 prompt "AMD MCE features"
881 depends on X86_MCE && X86_LOCAL_APIC
882 ---help---
883 Additional support for AMD specific MCE features such as
884 the DRAM Error Threshold.
885
886 config X86_ANCIENT_MCE
887 bool "Support for old Pentium 5 / WinChip machine checks"
888 depends on X86_32 && X86_MCE
889 ---help---
890 Include support for machine check handling on old Pentium 5 or WinChip
891 systems. These typically need to be enabled explicitly on the command
892 line.
893
894 config X86_MCE_THRESHOLD
895 depends on X86_MCE_AMD || X86_MCE_INTEL
896 def_bool y
897
898 config X86_MCE_INJECT
899 depends on X86_MCE
900 tristate "Machine check injector support"
901 ---help---
902 Provide support for injecting machine checks for testing purposes.
903 If you don't know what a machine check is and you don't do kernel
904 QA it is safe to say n.
905
906 config X86_THERMAL_VECTOR
907 def_bool y
908 depends on X86_MCE_INTEL
909
910 config VM86
911 bool "Enable VM86 support" if EXPERT
912 default y
913 depends on X86_32
914 ---help---
915 This option is required by programs like DOSEMU to run 16-bit legacy
916 code on X86 processors. It also may be needed by software like
917 XFree86 to initialize some video cards via BIOS. Disabling this
918 option saves about 6k.
919
920 config TOSHIBA
921 tristate "Toshiba Laptop support"
922 depends on X86_32
923 ---help---
924 This adds a driver to safely access the System Management Mode of
925 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
926 not work on models with a Phoenix BIOS. The System Management Mode
927 is used to set the BIOS and power saving options on Toshiba portables.
928
929 For information on utilities to make use of this driver see the
930 Toshiba Linux utilities web site at:
931 <http://www.buzzard.org.uk/toshiba/>.
932
933 Say Y if you intend to run this kernel on a Toshiba portable.
934 Say N otherwise.
935
936 config I8K
937 tristate "Dell laptop support"
938 select HWMON
939 ---help---
940 This adds a driver to safely access the System Management Mode
941 of the CPU on the Dell Inspiron 8000. The System Management Mode
942 is used to read cpu temperature and cooling fan status and to
943 control the fans on the I8K portables.
944
945 This driver has been tested only on the Inspiron 8000 but it may
946 also work with other Dell laptops. You can force loading on other
947 models by passing the parameter `force=1' to the module. Use at
948 your own risk.
949
950 For information on utilities to make use of this driver see the
951 I8K Linux utilities web site at:
952 <http://people.debian.org/~dz/i8k/>
953
954 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
955 Say N otherwise.
956
957 config X86_REBOOTFIXUPS
958 bool "Enable X86 board specific fixups for reboot"
959 depends on X86_32
960 ---help---
961 This enables chipset and/or board specific fixups to be done
962 in order to get reboot to work correctly. This is only needed on
963 some combinations of hardware and BIOS. The symptom, for which
964 this config is intended, is when reboot ends with a stalled/hung
965 system.
966
967 Currently, the only fixup is for the Geode machines using
968 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
969
970 Say Y if you want to enable the fixup. Currently, it's safe to
971 enable this option even if you don't need it.
972 Say N otherwise.
973
974 config MICROCODE
975 tristate "CPU microcode loading support"
976 depends on CPU_SUP_AMD || CPU_SUP_INTEL
977 select FW_LOADER
978 ---help---
979
980 If you say Y here, you will be able to update the microcode on
981 certain Intel and AMD processors. The Intel support is for the
982 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
983 Xeon etc. The AMD support is for families 0x10 and later. You will
984 obviously need the actual microcode binary data itself which is not
985 shipped with the Linux kernel.
986
987 This option selects the general module only, you need to select
988 at least one vendor specific module as well.
989
990 To compile this driver as a module, choose M here: the module
991 will be called microcode.
992
993 config MICROCODE_INTEL
994 bool "Intel microcode loading support"
995 depends on MICROCODE
996 default MICROCODE
997 select FW_LOADER
998 ---help---
999 This options enables microcode patch loading support for Intel
1000 processors.
1001
1002 For the current Intel microcode data package go to
1003 <https://downloadcenter.intel.com> and search for
1004 'Linux Processor Microcode Data File'.
1005
1006 config MICROCODE_AMD
1007 bool "AMD microcode loading support"
1008 depends on MICROCODE
1009 select FW_LOADER
1010 ---help---
1011 If you select this option, microcode patch loading support for AMD
1012 processors will be enabled.
1013
1014 config MICROCODE_OLD_INTERFACE
1015 def_bool y
1016 depends on MICROCODE
1017
1018 config MICROCODE_INTEL_EARLY
1019 def_bool n
1020
1021 config MICROCODE_AMD_EARLY
1022 def_bool n
1023
1024 config MICROCODE_EARLY
1025 bool "Early load microcode"
1026 depends on MICROCODE=y && BLK_DEV_INITRD
1027 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1028 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1029 default y
1030 help
1031 This option provides functionality to read additional microcode data
1032 at the beginning of initrd image. The data tells kernel to load
1033 microcode to CPU's as early as possible. No functional change if no
1034 microcode data is glued to the initrd, therefore it's safe to say Y.
1035
1036 config X86_MSR
1037 tristate "/dev/cpu/*/msr - Model-specific register support"
1038 ---help---
1039 This device gives privileged processes access to the x86
1040 Model-Specific Registers (MSRs). It is a character device with
1041 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1042 MSR accesses are directed to a specific CPU on multi-processor
1043 systems.
1044
1045 config X86_CPUID
1046 tristate "/dev/cpu/*/cpuid - CPU information support"
1047 ---help---
1048 This device gives processes access to the x86 CPUID instruction to
1049 be executed on a specific processor. It is a character device
1050 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1051 /dev/cpu/31/cpuid.
1052
1053 choice
1054 prompt "High Memory Support"
1055 default HIGHMEM4G
1056 depends on X86_32
1057
1058 config NOHIGHMEM
1059 bool "off"
1060 ---help---
1061 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1062 However, the address space of 32-bit x86 processors is only 4
1063 Gigabytes large. That means that, if you have a large amount of
1064 physical memory, not all of it can be "permanently mapped" by the
1065 kernel. The physical memory that's not permanently mapped is called
1066 "high memory".
1067
1068 If you are compiling a kernel which will never run on a machine with
1069 more than 1 Gigabyte total physical RAM, answer "off" here (default
1070 choice and suitable for most users). This will result in a "3GB/1GB"
1071 split: 3GB are mapped so that each process sees a 3GB virtual memory
1072 space and the remaining part of the 4GB virtual memory space is used
1073 by the kernel to permanently map as much physical memory as
1074 possible.
1075
1076 If the machine has between 1 and 4 Gigabytes physical RAM, then
1077 answer "4GB" here.
1078
1079 If more than 4 Gigabytes is used then answer "64GB" here. This
1080 selection turns Intel PAE (Physical Address Extension) mode on.
1081 PAE implements 3-level paging on IA32 processors. PAE is fully
1082 supported by Linux, PAE mode is implemented on all recent Intel
1083 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1084 then the kernel will not boot on CPUs that don't support PAE!
1085
1086 The actual amount of total physical memory will either be
1087 auto detected or can be forced by using a kernel command line option
1088 such as "mem=256M". (Try "man bootparam" or see the documentation of
1089 your boot loader (lilo or loadlin) about how to pass options to the
1090 kernel at boot time.)
1091
1092 If unsure, say "off".
1093
1094 config HIGHMEM4G
1095 bool "4GB"
1096 ---help---
1097 Select this if you have a 32-bit processor and between 1 and 4
1098 gigabytes of physical RAM.
1099
1100 config HIGHMEM64G
1101 bool "64GB"
1102 depends on !M486
1103 select X86_PAE
1104 ---help---
1105 Select this if you have a 32-bit processor and more than 4
1106 gigabytes of physical RAM.
1107
1108 endchoice
1109
1110 choice
1111 prompt "Memory split" if EXPERT
1112 default VMSPLIT_3G
1113 depends on X86_32
1114 ---help---
1115 Select the desired split between kernel and user memory.
1116
1117 If the address range available to the kernel is less than the
1118 physical memory installed, the remaining memory will be available
1119 as "high memory". Accessing high memory is a little more costly
1120 than low memory, as it needs to be mapped into the kernel first.
1121 Note that increasing the kernel address space limits the range
1122 available to user programs, making the address space there
1123 tighter. Selecting anything other than the default 3G/1G split
1124 will also likely make your kernel incompatible with binary-only
1125 kernel modules.
1126
1127 If you are not absolutely sure what you are doing, leave this
1128 option alone!
1129
1130 config VMSPLIT_3G
1131 bool "3G/1G user/kernel split"
1132 config VMSPLIT_3G_OPT
1133 depends on !X86_PAE
1134 bool "3G/1G user/kernel split (for full 1G low memory)"
1135 config VMSPLIT_2G
1136 bool "2G/2G user/kernel split"
1137 config VMSPLIT_2G_OPT
1138 depends on !X86_PAE
1139 bool "2G/2G user/kernel split (for full 2G low memory)"
1140 config VMSPLIT_1G
1141 bool "1G/3G user/kernel split"
1142 endchoice
1143
1144 config PAGE_OFFSET
1145 hex
1146 default 0xB0000000 if VMSPLIT_3G_OPT
1147 default 0x80000000 if VMSPLIT_2G
1148 default 0x78000000 if VMSPLIT_2G_OPT
1149 default 0x40000000 if VMSPLIT_1G
1150 default 0xC0000000
1151 depends on X86_32
1152
1153 config HIGHMEM
1154 def_bool y
1155 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1156
1157 config X86_PAE
1158 bool "PAE (Physical Address Extension) Support"
1159 depends on X86_32 && !HIGHMEM4G
1160 ---help---
1161 PAE is required for NX support, and furthermore enables
1162 larger swapspace support for non-overcommit purposes. It
1163 has the cost of more pagetable lookup overhead, and also
1164 consumes more pagetable space per process.
1165
1166 config ARCH_PHYS_ADDR_T_64BIT
1167 def_bool y
1168 depends on X86_64 || X86_PAE
1169
1170 config ARCH_DMA_ADDR_T_64BIT
1171 def_bool y
1172 depends on X86_64 || HIGHMEM64G
1173
1174 config DIRECT_GBPAGES
1175 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1176 default y
1177 depends on X86_64
1178 ---help---
1179 Allow the kernel linear mapping to use 1GB pages on CPUs that
1180 support it. This can improve the kernel's performance a tiny bit by
1181 reducing TLB pressure. If in doubt, say "Y".
1182
1183 # Common NUMA Features
1184 config NUMA
1185 bool "Numa Memory Allocation and Scheduler Support"
1186 depends on SMP
1187 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1188 default y if X86_BIGSMP
1189 ---help---
1190 Enable NUMA (Non Uniform Memory Access) support.
1191
1192 The kernel will try to allocate memory used by a CPU on the
1193 local memory controller of the CPU and add some more
1194 NUMA awareness to the kernel.
1195
1196 For 64-bit this is recommended if the system is Intel Core i7
1197 (or later), AMD Opteron, or EM64T NUMA.
1198
1199 For 32-bit this is only needed if you boot a 32-bit
1200 kernel on a 64-bit NUMA platform.
1201
1202 Otherwise, you should say N.
1203
1204 config AMD_NUMA
1205 def_bool y
1206 prompt "Old style AMD Opteron NUMA detection"
1207 depends on X86_64 && NUMA && PCI
1208 ---help---
1209 Enable AMD NUMA node topology detection. You should say Y here if
1210 you have a multi processor AMD system. This uses an old method to
1211 read the NUMA configuration directly from the builtin Northbridge
1212 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1213 which also takes priority if both are compiled in.
1214
1215 config X86_64_ACPI_NUMA
1216 def_bool y
1217 prompt "ACPI NUMA detection"
1218 depends on X86_64 && NUMA && ACPI && PCI
1219 select ACPI_NUMA
1220 ---help---
1221 Enable ACPI SRAT based node topology detection.
1222
1223 # Some NUMA nodes have memory ranges that span
1224 # other nodes. Even though a pfn is valid and
1225 # between a node's start and end pfns, it may not
1226 # reside on that node. See memmap_init_zone()
1227 # for details.
1228 config NODES_SPAN_OTHER_NODES
1229 def_bool y
1230 depends on X86_64_ACPI_NUMA
1231
1232 config NUMA_EMU
1233 bool "NUMA emulation"
1234 depends on NUMA
1235 ---help---
1236 Enable NUMA emulation. A flat machine will be split
1237 into virtual nodes when booted with "numa=fake=N", where N is the
1238 number of nodes. This is only useful for debugging.
1239
1240 config NODES_SHIFT
1241 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1242 range 1 10
1243 default "10" if MAXSMP
1244 default "6" if X86_64
1245 default "3"
1246 depends on NEED_MULTIPLE_NODES
1247 ---help---
1248 Specify the maximum number of NUMA Nodes available on the target
1249 system. Increases memory reserved to accommodate various tables.
1250
1251 config ARCH_HAVE_MEMORY_PRESENT
1252 def_bool y
1253 depends on X86_32 && DISCONTIGMEM
1254
1255 config NEED_NODE_MEMMAP_SIZE
1256 def_bool y
1257 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1258
1259 config ARCH_FLATMEM_ENABLE
1260 def_bool y
1261 depends on X86_32 && !NUMA
1262
1263 config ARCH_DISCONTIGMEM_ENABLE
1264 def_bool y
1265 depends on NUMA && X86_32
1266
1267 config ARCH_DISCONTIGMEM_DEFAULT
1268 def_bool y
1269 depends on NUMA && X86_32
1270
1271 config ARCH_SPARSEMEM_ENABLE
1272 def_bool y
1273 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1274 select SPARSEMEM_STATIC if X86_32
1275 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1276
1277 config ARCH_SPARSEMEM_DEFAULT
1278 def_bool y
1279 depends on X86_64
1280
1281 config ARCH_SELECT_MEMORY_MODEL
1282 def_bool y
1283 depends on ARCH_SPARSEMEM_ENABLE
1284
1285 config ARCH_MEMORY_PROBE
1286 bool "Enable sysfs memory/probe interface"
1287 depends on X86_64 && MEMORY_HOTPLUG
1288 help
1289 This option enables a sysfs memory/probe interface for testing.
1290 See Documentation/memory-hotplug.txt for more information.
1291 If you are unsure how to answer this question, answer N.
1292
1293 config ARCH_PROC_KCORE_TEXT
1294 def_bool y
1295 depends on X86_64 && PROC_KCORE
1296
1297 config ILLEGAL_POINTER_VALUE
1298 hex
1299 default 0 if X86_32
1300 default 0xdead000000000000 if X86_64
1301
1302 source "mm/Kconfig"
1303
1304 config HIGHPTE
1305 bool "Allocate 3rd-level pagetables from highmem"
1306 depends on HIGHMEM
1307 ---help---
1308 The VM uses one page table entry for each page of physical memory.
1309 For systems with a lot of RAM, this can be wasteful of precious
1310 low memory. Setting this option will put user-space page table
1311 entries in high memory.
1312
1313 config X86_CHECK_BIOS_CORRUPTION
1314 bool "Check for low memory corruption"
1315 ---help---
1316 Periodically check for memory corruption in low memory, which
1317 is suspected to be caused by BIOS. Even when enabled in the
1318 configuration, it is disabled at runtime. Enable it by
1319 setting "memory_corruption_check=1" on the kernel command
1320 line. By default it scans the low 64k of memory every 60
1321 seconds; see the memory_corruption_check_size and
1322 memory_corruption_check_period parameters in
1323 Documentation/kernel-parameters.txt to adjust this.
1324
1325 When enabled with the default parameters, this option has
1326 almost no overhead, as it reserves a relatively small amount
1327 of memory and scans it infrequently. It both detects corruption
1328 and prevents it from affecting the running system.
1329
1330 It is, however, intended as a diagnostic tool; if repeatable
1331 BIOS-originated corruption always affects the same memory,
1332 you can use memmap= to prevent the kernel from using that
1333 memory.
1334
1335 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1336 bool "Set the default setting of memory_corruption_check"
1337 depends on X86_CHECK_BIOS_CORRUPTION
1338 default y
1339 ---help---
1340 Set whether the default state of memory_corruption_check is
1341 on or off.
1342
1343 config X86_RESERVE_LOW
1344 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1345 default 64
1346 range 4 640
1347 ---help---
1348 Specify the amount of low memory to reserve for the BIOS.
1349
1350 The first page contains BIOS data structures that the kernel
1351 must not use, so that page must always be reserved.
1352
1353 By default we reserve the first 64K of physical RAM, as a
1354 number of BIOSes are known to corrupt that memory range
1355 during events such as suspend/resume or monitor cable
1356 insertion, so it must not be used by the kernel.
1357
1358 You can set this to 4 if you are absolutely sure that you
1359 trust the BIOS to get all its memory reservations and usages
1360 right. If you know your BIOS have problems beyond the
1361 default 64K area, you can set this to 640 to avoid using the
1362 entire low memory range.
1363
1364 If you have doubts about the BIOS (e.g. suspend/resume does
1365 not work or there's kernel crashes after certain hardware
1366 hotplug events) then you might want to enable
1367 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1368 typical corruption patterns.
1369
1370 Leave this to the default value of 64 if you are unsure.
1371
1372 config MATH_EMULATION
1373 bool
1374 prompt "Math emulation" if X86_32
1375 ---help---
1376 Linux can emulate a math coprocessor (used for floating point
1377 operations) if you don't have one. 486DX and Pentium processors have
1378 a math coprocessor built in, 486SX and 386 do not, unless you added
1379 a 487DX or 387, respectively. (The messages during boot time can
1380 give you some hints here ["man dmesg"].) Everyone needs either a
1381 coprocessor or this emulation.
1382
1383 If you don't have a math coprocessor, you need to say Y here; if you
1384 say Y here even though you have a coprocessor, the coprocessor will
1385 be used nevertheless. (This behavior can be changed with the kernel
1386 command line option "no387", which comes handy if your coprocessor
1387 is broken. Try "man bootparam" or see the documentation of your boot
1388 loader (lilo or loadlin) about how to pass options to the kernel at
1389 boot time.) This means that it is a good idea to say Y here if you
1390 intend to use this kernel on different machines.
1391
1392 More information about the internals of the Linux math coprocessor
1393 emulation can be found in <file:arch/x86/math-emu/README>.
1394
1395 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1396 kernel, it won't hurt.
1397
1398 config MTRR
1399 def_bool y
1400 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1401 ---help---
1402 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1403 the Memory Type Range Registers (MTRRs) may be used to control
1404 processor access to memory ranges. This is most useful if you have
1405 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1406 allows bus write transfers to be combined into a larger transfer
1407 before bursting over the PCI/AGP bus. This can increase performance
1408 of image write operations 2.5 times or more. Saying Y here creates a
1409 /proc/mtrr file which may be used to manipulate your processor's
1410 MTRRs. Typically the X server should use this.
1411
1412 This code has a reasonably generic interface so that similar
1413 control registers on other processors can be easily supported
1414 as well:
1415
1416 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1417 Registers (ARRs) which provide a similar functionality to MTRRs. For
1418 these, the ARRs are used to emulate the MTRRs.
1419 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1420 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1421 write-combining. All of these processors are supported by this code
1422 and it makes sense to say Y here if you have one of them.
1423
1424 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1425 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1426 can lead to all sorts of problems, so it's good to say Y here.
1427
1428 You can safely say Y even if your machine doesn't have MTRRs, you'll
1429 just add about 9 KB to your kernel.
1430
1431 See <file:Documentation/x86/mtrr.txt> for more information.
1432
1433 config MTRR_SANITIZER
1434 def_bool y
1435 prompt "MTRR cleanup support"
1436 depends on MTRR
1437 ---help---
1438 Convert MTRR layout from continuous to discrete, so X drivers can
1439 add writeback entries.
1440
1441 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1442 The largest mtrr entry size for a continuous block can be set with
1443 mtrr_chunk_size.
1444
1445 If unsure, say Y.
1446
1447 config MTRR_SANITIZER_ENABLE_DEFAULT
1448 int "MTRR cleanup enable value (0-1)"
1449 range 0 1
1450 default "0"
1451 depends on MTRR_SANITIZER
1452 ---help---
1453 Enable mtrr cleanup default value
1454
1455 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1456 int "MTRR cleanup spare reg num (0-7)"
1457 range 0 7
1458 default "1"
1459 depends on MTRR_SANITIZER
1460 ---help---
1461 mtrr cleanup spare entries default, it can be changed via
1462 mtrr_spare_reg_nr=N on the kernel command line.
1463
1464 config X86_PAT
1465 def_bool y
1466 prompt "x86 PAT support" if EXPERT
1467 depends on MTRR
1468 ---help---
1469 Use PAT attributes to setup page level cache control.
1470
1471 PATs are the modern equivalents of MTRRs and are much more
1472 flexible than MTRRs.
1473
1474 Say N here if you see bootup problems (boot crash, boot hang,
1475 spontaneous reboots) or a non-working video driver.
1476
1477 If unsure, say Y.
1478
1479 config ARCH_USES_PG_UNCACHED
1480 def_bool y
1481 depends on X86_PAT
1482
1483 config ARCH_RANDOM
1484 def_bool y
1485 prompt "x86 architectural random number generator" if EXPERT
1486 ---help---
1487 Enable the x86 architectural RDRAND instruction
1488 (Intel Bull Mountain technology) to generate random numbers.
1489 If supported, this is a high bandwidth, cryptographically
1490 secure hardware random number generator.
1491
1492 config X86_SMAP
1493 def_bool y
1494 prompt "Supervisor Mode Access Prevention" if EXPERT
1495 ---help---
1496 Supervisor Mode Access Prevention (SMAP) is a security
1497 feature in newer Intel processors. There is a small
1498 performance cost if this enabled and turned on; there is
1499 also a small increase in the kernel size if this is enabled.
1500
1501 If unsure, say Y.
1502
1503 config EFI
1504 bool "EFI runtime service support"
1505 depends on ACPI
1506 select UCS2_STRING
1507 ---help---
1508 This enables the kernel to use EFI runtime services that are
1509 available (such as the EFI variable services).
1510
1511 This option is only useful on systems that have EFI firmware.
1512 In addition, you should use the latest ELILO loader available
1513 at <http://elilo.sourceforge.net> in order to take advantage
1514 of EFI runtime services. However, even with this option, the
1515 resultant kernel should continue to boot on existing non-EFI
1516 platforms.
1517
1518 config EFI_STUB
1519 bool "EFI stub support"
1520 depends on EFI
1521 ---help---
1522 This kernel feature allows a bzImage to be loaded directly
1523 by EFI firmware without the use of a bootloader.
1524
1525 See Documentation/efi-stub.txt for more information.
1526
1527 config EFI_MIXED
1528 bool "EFI mixed-mode support"
1529 depends on EFI_STUB && X86_64
1530 ---help---
1531 Enabling this feature allows a 64-bit kernel to be booted
1532 on a 32-bit firmware, provided that your CPU supports 64-bit
1533 mode.
1534
1535 Note that it is not possible to boot a mixed-mode enabled
1536 kernel via the EFI boot stub - a bootloader that supports
1537 the EFI handover protocol must be used.
1538
1539 If unsure, say N.
1540
1541 config SECCOMP
1542 def_bool y
1543 prompt "Enable seccomp to safely compute untrusted bytecode"
1544 ---help---
1545 This kernel feature is useful for number crunching applications
1546 that may need to compute untrusted bytecode during their
1547 execution. By using pipes or other transports made available to
1548 the process as file descriptors supporting the read/write
1549 syscalls, it's possible to isolate those applications in
1550 their own address space using seccomp. Once seccomp is
1551 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1552 and the task is only allowed to execute a few safe syscalls
1553 defined by each seccomp mode.
1554
1555 If unsure, say Y. Only embedded should say N here.
1556
1557 source kernel/Kconfig.hz
1558
1559 config KEXEC
1560 bool "kexec system call"
1561 ---help---
1562 kexec is a system call that implements the ability to shutdown your
1563 current kernel, and to start another kernel. It is like a reboot
1564 but it is independent of the system firmware. And like a reboot
1565 you can start any kernel with it, not just Linux.
1566
1567 The name comes from the similarity to the exec system call.
1568
1569 It is an ongoing process to be certain the hardware in a machine
1570 is properly shutdown, so do not be surprised if this code does not
1571 initially work for you. As of this writing the exact hardware
1572 interface is strongly in flux, so no good recommendation can be
1573 made.
1574
1575 config CRASH_DUMP
1576 bool "kernel crash dumps"
1577 depends on X86_64 || (X86_32 && HIGHMEM)
1578 ---help---
1579 Generate crash dump after being started by kexec.
1580 This should be normally only set in special crash dump kernels
1581 which are loaded in the main kernel with kexec-tools into
1582 a specially reserved region and then later executed after
1583 a crash by kdump/kexec. The crash dump kernel must be compiled
1584 to a memory address not used by the main kernel or BIOS using
1585 PHYSICAL_START, or it must be built as a relocatable image
1586 (CONFIG_RELOCATABLE=y).
1587 For more details see Documentation/kdump/kdump.txt
1588
1589 config KEXEC_JUMP
1590 bool "kexec jump"
1591 depends on KEXEC && HIBERNATION
1592 ---help---
1593 Jump between original kernel and kexeced kernel and invoke
1594 code in physical address mode via KEXEC
1595
1596 config PHYSICAL_START
1597 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1598 default "0x1000000"
1599 ---help---
1600 This gives the physical address where the kernel is loaded.
1601
1602 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1603 bzImage will decompress itself to above physical address and
1604 run from there. Otherwise, bzImage will run from the address where
1605 it has been loaded by the boot loader and will ignore above physical
1606 address.
1607
1608 In normal kdump cases one does not have to set/change this option
1609 as now bzImage can be compiled as a completely relocatable image
1610 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1611 address. This option is mainly useful for the folks who don't want
1612 to use a bzImage for capturing the crash dump and want to use a
1613 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1614 to be specifically compiled to run from a specific memory area
1615 (normally a reserved region) and this option comes handy.
1616
1617 So if you are using bzImage for capturing the crash dump,
1618 leave the value here unchanged to 0x1000000 and set
1619 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1620 for capturing the crash dump change this value to start of
1621 the reserved region. In other words, it can be set based on
1622 the "X" value as specified in the "crashkernel=YM@XM"
1623 command line boot parameter passed to the panic-ed
1624 kernel. Please take a look at Documentation/kdump/kdump.txt
1625 for more details about crash dumps.
1626
1627 Usage of bzImage for capturing the crash dump is recommended as
1628 one does not have to build two kernels. Same kernel can be used
1629 as production kernel and capture kernel. Above option should have
1630 gone away after relocatable bzImage support is introduced. But it
1631 is present because there are users out there who continue to use
1632 vmlinux for dump capture. This option should go away down the
1633 line.
1634
1635 Don't change this unless you know what you are doing.
1636
1637 config RELOCATABLE
1638 bool "Build a relocatable kernel"
1639 default y
1640 ---help---
1641 This builds a kernel image that retains relocation information
1642 so it can be loaded someplace besides the default 1MB.
1643 The relocations tend to make the kernel binary about 10% larger,
1644 but are discarded at runtime.
1645
1646 One use is for the kexec on panic case where the recovery kernel
1647 must live at a different physical address than the primary
1648 kernel.
1649
1650 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1651 it has been loaded at and the compile time physical address
1652 (CONFIG_PHYSICAL_START) is used as the minimum location.
1653
1654 config RANDOMIZE_BASE
1655 bool "Randomize the address of the kernel image"
1656 depends on RELOCATABLE
1657 depends on !HIBERNATION
1658 default n
1659 ---help---
1660 Randomizes the physical and virtual address at which the
1661 kernel image is decompressed, as a security feature that
1662 deters exploit attempts relying on knowledge of the location
1663 of kernel internals.
1664
1665 Entropy is generated using the RDRAND instruction if it is
1666 supported. If RDTSC is supported, it is used as well. If
1667 neither RDRAND nor RDTSC are supported, then randomness is
1668 read from the i8254 timer.
1669
1670 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1671 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1672 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1673 minimum of 2MiB, only 10 bits of entropy is theoretically
1674 possible. At best, due to page table layouts, 64-bit can use
1675 9 bits of entropy and 32-bit uses 8 bits.
1676
1677 If unsure, say N.
1678
1679 config RANDOMIZE_BASE_MAX_OFFSET
1680 hex "Maximum kASLR offset allowed" if EXPERT
1681 depends on RANDOMIZE_BASE
1682 range 0x0 0x20000000 if X86_32
1683 default "0x20000000" if X86_32
1684 range 0x0 0x40000000 if X86_64
1685 default "0x40000000" if X86_64
1686 ---help---
1687 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1688 memory is used to determine the maximal offset in bytes that will
1689 be applied to the kernel when kernel Address Space Layout
1690 Randomization (kASLR) is active. This must be a multiple of
1691 PHYSICAL_ALIGN.
1692
1693 On 32-bit this is limited to 512MiB by page table layouts. The
1694 default is 512MiB.
1695
1696 On 64-bit this is limited by how the kernel fixmap page table is
1697 positioned, so this cannot be larger than 1GiB currently. Without
1698 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1699 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1700 modules area will shrink to compensate, up to the current maximum
1701 1GiB to 1GiB split. The default is 1GiB.
1702
1703 If unsure, leave at the default value.
1704
1705 # Relocation on x86 needs some additional build support
1706 config X86_NEED_RELOCS
1707 def_bool y
1708 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1709
1710 config PHYSICAL_ALIGN
1711 hex "Alignment value to which kernel should be aligned"
1712 default "0x200000"
1713 range 0x2000 0x1000000 if X86_32
1714 range 0x200000 0x1000000 if X86_64
1715 ---help---
1716 This value puts the alignment restrictions on physical address
1717 where kernel is loaded and run from. Kernel is compiled for an
1718 address which meets above alignment restriction.
1719
1720 If bootloader loads the kernel at a non-aligned address and
1721 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1722 address aligned to above value and run from there.
1723
1724 If bootloader loads the kernel at a non-aligned address and
1725 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1726 load address and decompress itself to the address it has been
1727 compiled for and run from there. The address for which kernel is
1728 compiled already meets above alignment restrictions. Hence the
1729 end result is that kernel runs from a physical address meeting
1730 above alignment restrictions.
1731
1732 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1733 this value must be a multiple of 0x200000.
1734
1735 Don't change this unless you know what you are doing.
1736
1737 config HOTPLUG_CPU
1738 bool "Support for hot-pluggable CPUs"
1739 depends on SMP
1740 ---help---
1741 Say Y here to allow turning CPUs off and on. CPUs can be
1742 controlled through /sys/devices/system/cpu.
1743 ( Note: power management support will enable this option
1744 automatically on SMP systems. )
1745 Say N if you want to disable CPU hotplug.
1746
1747 config BOOTPARAM_HOTPLUG_CPU0
1748 bool "Set default setting of cpu0_hotpluggable"
1749 default n
1750 depends on HOTPLUG_CPU
1751 ---help---
1752 Set whether default state of cpu0_hotpluggable is on or off.
1753
1754 Say Y here to enable CPU0 hotplug by default. If this switch
1755 is turned on, there is no need to give cpu0_hotplug kernel
1756 parameter and the CPU0 hotplug feature is enabled by default.
1757
1758 Please note: there are two known CPU0 dependencies if you want
1759 to enable the CPU0 hotplug feature either by this switch or by
1760 cpu0_hotplug kernel parameter.
1761
1762 First, resume from hibernate or suspend always starts from CPU0.
1763 So hibernate and suspend are prevented if CPU0 is offline.
1764
1765 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1766 offline if any interrupt can not migrate out of CPU0. There may
1767 be other CPU0 dependencies.
1768
1769 Please make sure the dependencies are under your control before
1770 you enable this feature.
1771
1772 Say N if you don't want to enable CPU0 hotplug feature by default.
1773 You still can enable the CPU0 hotplug feature at boot by kernel
1774 parameter cpu0_hotplug.
1775
1776 config DEBUG_HOTPLUG_CPU0
1777 def_bool n
1778 prompt "Debug CPU0 hotplug"
1779 depends on HOTPLUG_CPU
1780 ---help---
1781 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1782 soon as possible and boots up userspace with CPU0 offlined. User
1783 can online CPU0 back after boot time.
1784
1785 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1786 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1787 compilation or giving cpu0_hotplug kernel parameter at boot.
1788
1789 If unsure, say N.
1790
1791 config COMPAT_VDSO
1792 def_bool n
1793 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1794 depends on X86_32 || IA32_EMULATION
1795 ---help---
1796 Certain buggy versions of glibc will crash if they are
1797 presented with a 32-bit vDSO that is not mapped at the address
1798 indicated in its segment table.
1799
1800 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1801 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1802 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1803 the only released version with the bug, but OpenSUSE 9
1804 contains a buggy "glibc 2.3.2".
1805
1806 The symptom of the bug is that everything crashes on startup, saying:
1807 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1808
1809 Saying Y here changes the default value of the vdso32 boot
1810 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1811 This works around the glibc bug but hurts performance.
1812
1813 If unsure, say N: if you are compiling your own kernel, you
1814 are unlikely to be using a buggy version of glibc.
1815
1816 config CMDLINE_BOOL
1817 bool "Built-in kernel command line"
1818 ---help---
1819 Allow for specifying boot arguments to the kernel at
1820 build time. On some systems (e.g. embedded ones), it is
1821 necessary or convenient to provide some or all of the
1822 kernel boot arguments with the kernel itself (that is,
1823 to not rely on the boot loader to provide them.)
1824
1825 To compile command line arguments into the kernel,
1826 set this option to 'Y', then fill in the
1827 the boot arguments in CONFIG_CMDLINE.
1828
1829 Systems with fully functional boot loaders (i.e. non-embedded)
1830 should leave this option set to 'N'.
1831
1832 config CMDLINE
1833 string "Built-in kernel command string"
1834 depends on CMDLINE_BOOL
1835 default ""
1836 ---help---
1837 Enter arguments here that should be compiled into the kernel
1838 image and used at boot time. If the boot loader provides a
1839 command line at boot time, it is appended to this string to
1840 form the full kernel command line, when the system boots.
1841
1842 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1843 change this behavior.
1844
1845 In most cases, the command line (whether built-in or provided
1846 by the boot loader) should specify the device for the root
1847 file system.
1848
1849 config CMDLINE_OVERRIDE
1850 bool "Built-in command line overrides boot loader arguments"
1851 depends on CMDLINE_BOOL
1852 ---help---
1853 Set this option to 'Y' to have the kernel ignore the boot loader
1854 command line, and use ONLY the built-in command line.
1855
1856 This is used to work around broken boot loaders. This should
1857 be set to 'N' under normal conditions.
1858
1859 endmenu
1860
1861 config ARCH_ENABLE_MEMORY_HOTPLUG
1862 def_bool y
1863 depends on X86_64 || (X86_32 && HIGHMEM)
1864
1865 config ARCH_ENABLE_MEMORY_HOTREMOVE
1866 def_bool y
1867 depends on MEMORY_HOTPLUG
1868
1869 config USE_PERCPU_NUMA_NODE_ID
1870 def_bool y
1871 depends on NUMA
1872
1873 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1874 def_bool y
1875 depends on X86_64 || X86_PAE
1876
1877 menu "Power management and ACPI options"
1878
1879 config ARCH_HIBERNATION_HEADER
1880 def_bool y
1881 depends on X86_64 && HIBERNATION
1882
1883 source "kernel/power/Kconfig"
1884
1885 source "drivers/acpi/Kconfig"
1886
1887 source "drivers/sfi/Kconfig"
1888
1889 config X86_APM_BOOT
1890 def_bool y
1891 depends on APM
1892
1893 menuconfig APM
1894 tristate "APM (Advanced Power Management) BIOS support"
1895 depends on X86_32 && PM_SLEEP
1896 ---help---
1897 APM is a BIOS specification for saving power using several different
1898 techniques. This is mostly useful for battery powered laptops with
1899 APM compliant BIOSes. If you say Y here, the system time will be
1900 reset after a RESUME operation, the /proc/apm device will provide
1901 battery status information, and user-space programs will receive
1902 notification of APM "events" (e.g. battery status change).
1903
1904 If you select "Y" here, you can disable actual use of the APM
1905 BIOS by passing the "apm=off" option to the kernel at boot time.
1906
1907 Note that the APM support is almost completely disabled for
1908 machines with more than one CPU.
1909
1910 In order to use APM, you will need supporting software. For location
1911 and more information, read <file:Documentation/power/apm-acpi.txt>
1912 and the Battery Powered Linux mini-HOWTO, available from
1913 <http://www.tldp.org/docs.html#howto>.
1914
1915 This driver does not spin down disk drives (see the hdparm(8)
1916 manpage ("man 8 hdparm") for that), and it doesn't turn off
1917 VESA-compliant "green" monitors.
1918
1919 This driver does not support the TI 4000M TravelMate and the ACER
1920 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1921 desktop machines also don't have compliant BIOSes, and this driver
1922 may cause those machines to panic during the boot phase.
1923
1924 Generally, if you don't have a battery in your machine, there isn't
1925 much point in using this driver and you should say N. If you get
1926 random kernel OOPSes or reboots that don't seem to be related to
1927 anything, try disabling/enabling this option (or disabling/enabling
1928 APM in your BIOS).
1929
1930 Some other things you should try when experiencing seemingly random,
1931 "weird" problems:
1932
1933 1) make sure that you have enough swap space and that it is
1934 enabled.
1935 2) pass the "no-hlt" option to the kernel
1936 3) switch on floating point emulation in the kernel and pass
1937 the "no387" option to the kernel
1938 4) pass the "floppy=nodma" option to the kernel
1939 5) pass the "mem=4M" option to the kernel (thereby disabling
1940 all but the first 4 MB of RAM)
1941 6) make sure that the CPU is not over clocked.
1942 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1943 8) disable the cache from your BIOS settings
1944 9) install a fan for the video card or exchange video RAM
1945 10) install a better fan for the CPU
1946 11) exchange RAM chips
1947 12) exchange the motherboard.
1948
1949 To compile this driver as a module, choose M here: the
1950 module will be called apm.
1951
1952 if APM
1953
1954 config APM_IGNORE_USER_SUSPEND
1955 bool "Ignore USER SUSPEND"
1956 ---help---
1957 This option will ignore USER SUSPEND requests. On machines with a
1958 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1959 series notebooks, it is necessary to say Y because of a BIOS bug.
1960
1961 config APM_DO_ENABLE
1962 bool "Enable PM at boot time"
1963 ---help---
1964 Enable APM features at boot time. From page 36 of the APM BIOS
1965 specification: "When disabled, the APM BIOS does not automatically
1966 power manage devices, enter the Standby State, enter the Suspend
1967 State, or take power saving steps in response to CPU Idle calls."
1968 This driver will make CPU Idle calls when Linux is idle (unless this
1969 feature is turned off -- see "Do CPU IDLE calls", below). This
1970 should always save battery power, but more complicated APM features
1971 will be dependent on your BIOS implementation. You may need to turn
1972 this option off if your computer hangs at boot time when using APM
1973 support, or if it beeps continuously instead of suspending. Turn
1974 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1975 T400CDT. This is off by default since most machines do fine without
1976 this feature.
1977
1978 config APM_CPU_IDLE
1979 depends on CPU_IDLE
1980 bool "Make CPU Idle calls when idle"
1981 ---help---
1982 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1983 On some machines, this can activate improved power savings, such as
1984 a slowed CPU clock rate, when the machine is idle. These idle calls
1985 are made after the idle loop has run for some length of time (e.g.,
1986 333 mS). On some machines, this will cause a hang at boot time or
1987 whenever the CPU becomes idle. (On machines with more than one CPU,
1988 this option does nothing.)
1989
1990 config APM_DISPLAY_BLANK
1991 bool "Enable console blanking using APM"
1992 ---help---
1993 Enable console blanking using the APM. Some laptops can use this to
1994 turn off the LCD backlight when the screen blanker of the Linux
1995 virtual console blanks the screen. Note that this is only used by
1996 the virtual console screen blanker, and won't turn off the backlight
1997 when using the X Window system. This also doesn't have anything to
1998 do with your VESA-compliant power-saving monitor. Further, this
1999 option doesn't work for all laptops -- it might not turn off your
2000 backlight at all, or it might print a lot of errors to the console,
2001 especially if you are using gpm.
2002
2003 config APM_ALLOW_INTS
2004 bool "Allow interrupts during APM BIOS calls"
2005 ---help---
2006 Normally we disable external interrupts while we are making calls to
2007 the APM BIOS as a measure to lessen the effects of a badly behaving
2008 BIOS implementation. The BIOS should reenable interrupts if it
2009 needs to. Unfortunately, some BIOSes do not -- especially those in
2010 many of the newer IBM Thinkpads. If you experience hangs when you
2011 suspend, try setting this to Y. Otherwise, say N.
2012
2013 endif # APM
2014
2015 source "drivers/cpufreq/Kconfig"
2016
2017 source "drivers/cpuidle/Kconfig"
2018
2019 source "drivers/idle/Kconfig"
2020
2021 endmenu
2022
2023
2024 menu "Bus options (PCI etc.)"
2025
2026 config PCI
2027 bool "PCI support"
2028 default y
2029 ---help---
2030 Find out whether you have a PCI motherboard. PCI is the name of a
2031 bus system, i.e. the way the CPU talks to the other stuff inside
2032 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2033 VESA. If you have PCI, say Y, otherwise N.
2034
2035 choice
2036 prompt "PCI access mode"
2037 depends on X86_32 && PCI
2038 default PCI_GOANY
2039 ---help---
2040 On PCI systems, the BIOS can be used to detect the PCI devices and
2041 determine their configuration. However, some old PCI motherboards
2042 have BIOS bugs and may crash if this is done. Also, some embedded
2043 PCI-based systems don't have any BIOS at all. Linux can also try to
2044 detect the PCI hardware directly without using the BIOS.
2045
2046 With this option, you can specify how Linux should detect the
2047 PCI devices. If you choose "BIOS", the BIOS will be used,
2048 if you choose "Direct", the BIOS won't be used, and if you
2049 choose "MMConfig", then PCI Express MMCONFIG will be used.
2050 If you choose "Any", the kernel will try MMCONFIG, then the
2051 direct access method and falls back to the BIOS if that doesn't
2052 work. If unsure, go with the default, which is "Any".
2053
2054 config PCI_GOBIOS
2055 bool "BIOS"
2056
2057 config PCI_GOMMCONFIG
2058 bool "MMConfig"
2059
2060 config PCI_GODIRECT
2061 bool "Direct"
2062
2063 config PCI_GOOLPC
2064 bool "OLPC XO-1"
2065 depends on OLPC
2066
2067 config PCI_GOANY
2068 bool "Any"
2069
2070 endchoice
2071
2072 config PCI_BIOS
2073 def_bool y
2074 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2075
2076 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2077 config PCI_DIRECT
2078 def_bool y
2079 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2080
2081 config PCI_MMCONFIG
2082 def_bool y
2083 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2084
2085 config PCI_OLPC
2086 def_bool y
2087 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2088
2089 config PCI_XEN
2090 def_bool y
2091 depends on PCI && XEN
2092 select SWIOTLB_XEN
2093
2094 config PCI_DOMAINS
2095 def_bool y
2096 depends on PCI
2097
2098 config PCI_MMCONFIG
2099 bool "Support mmconfig PCI config space access"
2100 depends on X86_64 && PCI && ACPI
2101
2102 config PCI_CNB20LE_QUIRK
2103 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2104 depends on PCI
2105 help
2106 Read the PCI windows out of the CNB20LE host bridge. This allows
2107 PCI hotplug to work on systems with the CNB20LE chipset which do
2108 not have ACPI.
2109
2110 There's no public spec for this chipset, and this functionality
2111 is known to be incomplete.
2112
2113 You should say N unless you know you need this.
2114
2115 source "drivers/pci/pcie/Kconfig"
2116
2117 source "drivers/pci/Kconfig"
2118
2119 # x86_64 have no ISA slots, but can have ISA-style DMA.
2120 config ISA_DMA_API
2121 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2122 default y
2123 help
2124 Enables ISA-style DMA support for devices requiring such controllers.
2125 If unsure, say Y.
2126
2127 if X86_32
2128
2129 config ISA
2130 bool "ISA support"
2131 ---help---
2132 Find out whether you have ISA slots on your motherboard. ISA is the
2133 name of a bus system, i.e. the way the CPU talks to the other stuff
2134 inside your box. Other bus systems are PCI, EISA, MicroChannel
2135 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2136 newer boards don't support it. If you have ISA, say Y, otherwise N.
2137
2138 config EISA
2139 bool "EISA support"
2140 depends on ISA
2141 ---help---
2142 The Extended Industry Standard Architecture (EISA) bus was
2143 developed as an open alternative to the IBM MicroChannel bus.
2144
2145 The EISA bus provided some of the features of the IBM MicroChannel
2146 bus while maintaining backward compatibility with cards made for
2147 the older ISA bus. The EISA bus saw limited use between 1988 and
2148 1995 when it was made obsolete by the PCI bus.
2149
2150 Say Y here if you are building a kernel for an EISA-based machine.
2151
2152 Otherwise, say N.
2153
2154 source "drivers/eisa/Kconfig"
2155
2156 config SCx200
2157 tristate "NatSemi SCx200 support"
2158 ---help---
2159 This provides basic support for National Semiconductor's
2160 (now AMD's) Geode processors. The driver probes for the
2161 PCI-IDs of several on-chip devices, so its a good dependency
2162 for other scx200_* drivers.
2163
2164 If compiled as a module, the driver is named scx200.
2165
2166 config SCx200HR_TIMER
2167 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2168 depends on SCx200
2169 default y
2170 ---help---
2171 This driver provides a clocksource built upon the on-chip
2172 27MHz high-resolution timer. Its also a workaround for
2173 NSC Geode SC-1100's buggy TSC, which loses time when the
2174 processor goes idle (as is done by the scheduler). The
2175 other workaround is idle=poll boot option.
2176
2177 config OLPC
2178 bool "One Laptop Per Child support"
2179 depends on !X86_PAE
2180 select GPIOLIB
2181 select OF
2182 select OF_PROMTREE
2183 select IRQ_DOMAIN
2184 ---help---
2185 Add support for detecting the unique features of the OLPC
2186 XO hardware.
2187
2188 config OLPC_XO1_PM
2189 bool "OLPC XO-1 Power Management"
2190 depends on OLPC && MFD_CS5535 && PM_SLEEP
2191 select MFD_CORE
2192 ---help---
2193 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2194
2195 config OLPC_XO1_RTC
2196 bool "OLPC XO-1 Real Time Clock"
2197 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2198 ---help---
2199 Add support for the XO-1 real time clock, which can be used as a
2200 programmable wakeup source.
2201
2202 config OLPC_XO1_SCI
2203 bool "OLPC XO-1 SCI extras"
2204 depends on OLPC && OLPC_XO1_PM
2205 depends on INPUT=y
2206 select POWER_SUPPLY
2207 select GPIO_CS5535
2208 select MFD_CORE
2209 ---help---
2210 Add support for SCI-based features of the OLPC XO-1 laptop:
2211 - EC-driven system wakeups
2212 - Power button
2213 - Ebook switch
2214 - Lid switch
2215 - AC adapter status updates
2216 - Battery status updates
2217
2218 config OLPC_XO15_SCI
2219 bool "OLPC XO-1.5 SCI extras"
2220 depends on OLPC && ACPI
2221 select POWER_SUPPLY
2222 ---help---
2223 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2224 - EC-driven system wakeups
2225 - AC adapter status updates
2226 - Battery status updates
2227
2228 config ALIX
2229 bool "PCEngines ALIX System Support (LED setup)"
2230 select GPIOLIB
2231 ---help---
2232 This option enables system support for the PCEngines ALIX.
2233 At present this just sets up LEDs for GPIO control on
2234 ALIX2/3/6 boards. However, other system specific setup should
2235 get added here.
2236
2237 Note: You must still enable the drivers for GPIO and LED support
2238 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2239
2240 Note: You have to set alix.force=1 for boards with Award BIOS.
2241
2242 config NET5501
2243 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2244 select GPIOLIB
2245 ---help---
2246 This option enables system support for the Soekris Engineering net5501.
2247
2248 config GEOS
2249 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2250 select GPIOLIB
2251 depends on DMI
2252 ---help---
2253 This option enables system support for the Traverse Technologies GEOS.
2254
2255 config TS5500
2256 bool "Technologic Systems TS-5500 platform support"
2257 depends on MELAN
2258 select CHECK_SIGNATURE
2259 select NEW_LEDS
2260 select LEDS_CLASS
2261 ---help---
2262 This option enables system support for the Technologic Systems TS-5500.
2263
2264 endif # X86_32
2265
2266 config AMD_NB
2267 def_bool y
2268 depends on CPU_SUP_AMD && PCI
2269
2270 source "drivers/pcmcia/Kconfig"
2271
2272 source "drivers/pci/hotplug/Kconfig"
2273
2274 config RAPIDIO
2275 tristate "RapidIO support"
2276 depends on PCI
2277 default n
2278 help
2279 If enabled this option will include drivers and the core
2280 infrastructure code to support RapidIO interconnect devices.
2281
2282 source "drivers/rapidio/Kconfig"
2283
2284 config X86_SYSFB
2285 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2286 help
2287 Firmwares often provide initial graphics framebuffers so the BIOS,
2288 bootloader or kernel can show basic video-output during boot for
2289 user-guidance and debugging. Historically, x86 used the VESA BIOS
2290 Extensions and EFI-framebuffers for this, which are mostly limited
2291 to x86.
2292 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2293 framebuffers so the new generic system-framebuffer drivers can be
2294 used on x86. If the framebuffer is not compatible with the generic
2295 modes, it is adverticed as fallback platform framebuffer so legacy
2296 drivers like efifb, vesafb and uvesafb can pick it up.
2297 If this option is not selected, all system framebuffers are always
2298 marked as fallback platform framebuffers as usual.
2299
2300 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2301 not be able to pick up generic system framebuffers if this option
2302 is selected. You are highly encouraged to enable simplefb as
2303 replacement if you select this option. simplefb can correctly deal
2304 with generic system framebuffers. But you should still keep vesafb
2305 and others enabled as fallback if a system framebuffer is
2306 incompatible with simplefb.
2307
2308 If unsure, say Y.
2309
2310 endmenu
2311
2312
2313 menu "Executable file formats / Emulations"
2314
2315 source "fs/Kconfig.binfmt"
2316
2317 config IA32_EMULATION
2318 bool "IA32 Emulation"
2319 depends on X86_64
2320 select BINFMT_ELF
2321 select COMPAT_BINFMT_ELF
2322 select HAVE_UID16
2323 ---help---
2324 Include code to run legacy 32-bit programs under a
2325 64-bit kernel. You should likely turn this on, unless you're
2326 100% sure that you don't have any 32-bit programs left.
2327
2328 config IA32_AOUT
2329 tristate "IA32 a.out support"
2330 depends on IA32_EMULATION
2331 ---help---
2332 Support old a.out binaries in the 32bit emulation.
2333
2334 config X86_X32
2335 bool "x32 ABI for 64-bit mode"
2336 depends on X86_64 && IA32_EMULATION
2337 ---help---
2338 Include code to run binaries for the x32 native 32-bit ABI
2339 for 64-bit processors. An x32 process gets access to the
2340 full 64-bit register file and wide data path while leaving
2341 pointers at 32 bits for smaller memory footprint.
2342
2343 You will need a recent binutils (2.22 or later) with
2344 elf32_x86_64 support enabled to compile a kernel with this
2345 option set.
2346
2347 config COMPAT
2348 def_bool y
2349 depends on IA32_EMULATION || X86_X32
2350 select ARCH_WANT_OLD_COMPAT_IPC
2351
2352 if COMPAT
2353 config COMPAT_FOR_U64_ALIGNMENT
2354 def_bool y
2355
2356 config SYSVIPC_COMPAT
2357 def_bool y
2358 depends on SYSVIPC
2359
2360 config KEYS_COMPAT
2361 def_bool y
2362 depends on KEYS
2363 endif
2364
2365 endmenu
2366
2367
2368 config HAVE_ATOMIC_IOMAP
2369 def_bool y
2370 depends on X86_32
2371
2372 config X86_DEV_DMA_OPS
2373 bool
2374 depends on X86_64 || STA2X11
2375
2376 config X86_DMA_REMAP
2377 bool
2378 depends on STA2X11
2379
2380 config IOSF_MBI
2381 bool
2382 depends on PCI
2383 ---help---
2384 To be selected by modules requiring access to the Intel OnChip System
2385 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2386 enumerable by PCI.
2387
2388 source "net/Kconfig"
2389
2390 source "drivers/Kconfig"
2391
2392 source "drivers/firmware/Kconfig"
2393
2394 source "fs/Kconfig"
2395
2396 source "arch/x86/Kconfig.debug"
2397
2398 source "security/Kconfig"
2399
2400 source "crypto/Kconfig"
2401
2402 source "arch/x86/kvm/Kconfig"
2403
2404 source "lib/Kconfig"
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