7d5feb5908ddeabf3fcab0a3114e2c318c0537d3
[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_EXTENDED_PLATFORM
422 ---help---
423 Enable support for the Goldfish virtual platform used primarily
424 for Android development. Unless you are building for the Android
425 Goldfish emulator say N here.
426
427 config X86_INTEL_CE
428 bool "CE4100 TV platform"
429 depends on PCI
430 depends on PCI_GODIRECT
431 depends on X86_32
432 depends on X86_EXTENDED_PLATFORM
433 select X86_REBOOTFIXUPS
434 select OF
435 select OF_EARLY_FLATTREE
436 select IRQ_DOMAIN
437 ---help---
438 Select for the Intel CE media processor (CE4100) SOC.
439 This option compiles in support for the CE4100 SOC for settop
440 boxes and media devices.
441
442 config X86_INTEL_MID
443 bool "Intel MID platform support"
444 depends on X86_32
445 depends on X86_EXTENDED_PLATFORM
446 depends on X86_PLATFORM_DEVICES
447 depends on PCI
448 depends on PCI_GOANY
449 depends on X86_IO_APIC
450 select SFI
451 select I2C
452 select DW_APB_TIMER
453 select APB_TIMER
454 select INTEL_SCU_IPC
455 select MFD_INTEL_MSIC
456 ---help---
457 Select to build a kernel capable of supporting Intel MID (Mobile
458 Internet Device) platform systems which do not have the PCI legacy
459 interfaces. If you are building for a PC class system say N here.
460
461 Intel MID platforms are based on an Intel processor and chipset which
462 consume less power than most of the x86 derivatives.
463
464 config X86_INTEL_LPSS
465 bool "Intel Low Power Subsystem Support"
466 depends on ACPI
467 select COMMON_CLK
468 select PINCTRL
469 ---help---
470 Select to build support for Intel Low Power Subsystem such as
471 found on Intel Lynxpoint PCH. Selecting this option enables
472 things like clock tree (common clock framework) and pincontrol
473 which are needed by the LPSS peripheral drivers.
474
475 config X86_RDC321X
476 bool "RDC R-321x SoC"
477 depends on X86_32
478 depends on X86_EXTENDED_PLATFORM
479 select M486
480 select X86_REBOOTFIXUPS
481 ---help---
482 This option is needed for RDC R-321x system-on-chip, also known
483 as R-8610-(G).
484 If you don't have one of these chips, you should say N here.
485
486 config X86_32_NON_STANDARD
487 bool "Support non-standard 32-bit SMP architectures"
488 depends on X86_32 && SMP
489 depends on X86_EXTENDED_PLATFORM
490 ---help---
491 This option compiles in the bigsmp and STA2X11 default
492 subarchitectures. It is intended for a generic binary
493 kernel. If you select them all, kernel will probe it one by
494 one and will fallback to default.
495
496 # Alphabetically sorted list of Non standard 32 bit platforms
497
498 config X86_SUPPORTS_MEMORY_FAILURE
499 def_bool y
500 # MCE code calls memory_failure():
501 depends on X86_MCE
502 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
503 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
504 depends on X86_64 || !SPARSEMEM
505 select ARCH_SUPPORTS_MEMORY_FAILURE
506
507 config STA2X11
508 bool "STA2X11 Companion Chip Support"
509 depends on X86_32_NON_STANDARD && PCI
510 select X86_DEV_DMA_OPS
511 select X86_DMA_REMAP
512 select SWIOTLB
513 select MFD_STA2X11
514 select ARCH_REQUIRE_GPIOLIB
515 default n
516 ---help---
517 This adds support for boards based on the STA2X11 IO-Hub,
518 a.k.a. "ConneXt". The chip is used in place of the standard
519 PC chipset, so all "standard" peripherals are missing. If this
520 option is selected the kernel will still be able to boot on
521 standard PC machines.
522
523 config X86_32_IRIS
524 tristate "Eurobraille/Iris poweroff module"
525 depends on X86_32
526 ---help---
527 The Iris machines from EuroBraille do not have APM or ACPI support
528 to shut themselves down properly. A special I/O sequence is
529 needed to do so, which is what this module does at
530 kernel shutdown.
531
532 This is only for Iris machines from EuroBraille.
533
534 If unused, say N.
535
536 config SCHED_OMIT_FRAME_POINTER
537 def_bool y
538 prompt "Single-depth WCHAN output"
539 depends on X86
540 ---help---
541 Calculate simpler /proc/<PID>/wchan values. If this option
542 is disabled then wchan values will recurse back to the
543 caller function. This provides more accurate wchan values,
544 at the expense of slightly more scheduling overhead.
545
546 If in doubt, say "Y".
547
548 menuconfig HYPERVISOR_GUEST
549 bool "Linux guest support"
550 ---help---
551 Say Y here to enable options for running Linux under various hyper-
552 visors. This option enables basic hypervisor detection and platform
553 setup.
554
555 If you say N, all options in this submenu will be skipped and
556 disabled, and Linux guest support won't be built in.
557
558 if HYPERVISOR_GUEST
559
560 config PARAVIRT
561 bool "Enable paravirtualization code"
562 ---help---
563 This changes the kernel so it can modify itself when it is run
564 under a hypervisor, potentially improving performance significantly
565 over full virtualization. However, when run without a hypervisor
566 the kernel is theoretically slower and slightly larger.
567
568 config PARAVIRT_DEBUG
569 bool "paravirt-ops debugging"
570 depends on PARAVIRT && DEBUG_KERNEL
571 ---help---
572 Enable to debug paravirt_ops internals. Specifically, BUG if
573 a paravirt_op is missing when it is called.
574
575 config PARAVIRT_SPINLOCKS
576 bool "Paravirtualization layer for spinlocks"
577 depends on PARAVIRT && SMP
578 select UNINLINE_SPIN_UNLOCK
579 ---help---
580 Paravirtualized spinlocks allow a pvops backend to replace the
581 spinlock implementation with something virtualization-friendly
582 (for example, block the virtual CPU rather than spinning).
583
584 It has a minimal impact on native kernels and gives a nice performance
585 benefit on paravirtualized KVM / Xen kernels.
586
587 If you are unsure how to answer this question, answer Y.
588
589 source "arch/x86/xen/Kconfig"
590
591 config KVM_GUEST
592 bool "KVM Guest support (including kvmclock)"
593 depends on PARAVIRT
594 select PARAVIRT_CLOCK
595 default y
596 ---help---
597 This option enables various optimizations for running under the KVM
598 hypervisor. It includes a paravirtualized clock, so that instead
599 of relying on a PIT (or probably other) emulation by the
600 underlying device model, the host provides the guest with
601 timing infrastructure such as time of day, and system time
602
603 config KVM_DEBUG_FS
604 bool "Enable debug information for KVM Guests in debugfs"
605 depends on KVM_GUEST && DEBUG_FS
606 default n
607 ---help---
608 This option enables collection of various statistics for KVM guest.
609 Statistics are displayed in debugfs filesystem. Enabling this option
610 may incur significant overhead.
611
612 source "arch/x86/lguest/Kconfig"
613
614 config PARAVIRT_TIME_ACCOUNTING
615 bool "Paravirtual steal time accounting"
616 depends on PARAVIRT
617 default n
618 ---help---
619 Select this option to enable fine granularity task steal time
620 accounting. Time spent executing other tasks in parallel with
621 the current vCPU is discounted from the vCPU power. To account for
622 that, there can be a small performance impact.
623
624 If in doubt, say N here.
625
626 config PARAVIRT_CLOCK
627 bool
628
629 endif #HYPERVISOR_GUEST
630
631 config NO_BOOTMEM
632 def_bool y
633
634 config MEMTEST
635 bool "Memtest"
636 ---help---
637 This option adds a kernel parameter 'memtest', which allows memtest
638 to be set.
639 memtest=0, mean disabled; -- default
640 memtest=1, mean do 1 test pattern;
641 ...
642 memtest=4, mean do 4 test patterns.
643 If you are unsure how to answer this question, answer N.
644
645 source "arch/x86/Kconfig.cpu"
646
647 config HPET_TIMER
648 def_bool X86_64
649 prompt "HPET Timer Support" if X86_32
650 ---help---
651 Use the IA-PC HPET (High Precision Event Timer) to manage
652 time in preference to the PIT and RTC, if a HPET is
653 present.
654 HPET is the next generation timer replacing legacy 8254s.
655 The HPET provides a stable time base on SMP
656 systems, unlike the TSC, but it is more expensive to access,
657 as it is off-chip. You can find the HPET spec at
658 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
659
660 You can safely choose Y here. However, HPET will only be
661 activated if the platform and the BIOS support this feature.
662 Otherwise the 8254 will be used for timing services.
663
664 Choose N to continue using the legacy 8254 timer.
665
666 config HPET_EMULATE_RTC
667 def_bool y
668 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
669
670 config APB_TIMER
671 def_bool y if X86_INTEL_MID
672 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
673 select DW_APB_TIMER
674 depends on X86_INTEL_MID && SFI
675 help
676 APB timer is the replacement for 8254, HPET on X86 MID platforms.
677 The APBT provides a stable time base on SMP
678 systems, unlike the TSC, but it is more expensive to access,
679 as it is off-chip. APB timers are always running regardless of CPU
680 C states, they are used as per CPU clockevent device when possible.
681
682 # Mark as expert because too many people got it wrong.
683 # The code disables itself when not needed.
684 config DMI
685 default y
686 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
687 bool "Enable DMI scanning" if EXPERT
688 ---help---
689 Enabled scanning of DMI to identify machine quirks. Say Y
690 here unless you have verified that your setup is not
691 affected by entries in the DMI blacklist. Required by PNP
692 BIOS code.
693
694 config GART_IOMMU
695 bool "Old AMD GART IOMMU support"
696 select SWIOTLB
697 depends on X86_64 && PCI && AMD_NB
698 ---help---
699 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
700 GART based hardware IOMMUs.
701
702 The GART supports full DMA access for devices with 32-bit access
703 limitations, on systems with more than 3 GB. This is usually needed
704 for USB, sound, many IDE/SATA chipsets and some other devices.
705
706 Newer systems typically have a modern AMD IOMMU, supported via
707 the CONFIG_AMD_IOMMU=y config option.
708
709 In normal configurations this driver is only active when needed:
710 there's more than 3 GB of memory and the system contains a
711 32-bit limited device.
712
713 If unsure, say Y.
714
715 config CALGARY_IOMMU
716 bool "IBM Calgary IOMMU support"
717 select SWIOTLB
718 depends on X86_64 && PCI
719 ---help---
720 Support for hardware IOMMUs in IBM's xSeries x366 and x460
721 systems. Needed to run systems with more than 3GB of memory
722 properly with 32-bit PCI devices that do not support DAC
723 (Double Address Cycle). Calgary also supports bus level
724 isolation, where all DMAs pass through the IOMMU. This
725 prevents them from going anywhere except their intended
726 destination. This catches hard-to-find kernel bugs and
727 mis-behaving drivers and devices that do not use the DMA-API
728 properly to set up their DMA buffers. The IOMMU can be
729 turned off at boot time with the iommu=off parameter.
730 Normally the kernel will make the right choice by itself.
731 If unsure, say Y.
732
733 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
734 def_bool y
735 prompt "Should Calgary be enabled by default?"
736 depends on CALGARY_IOMMU
737 ---help---
738 Should Calgary be enabled by default? if you choose 'y', Calgary
739 will be used (if it exists). If you choose 'n', Calgary will not be
740 used even if it exists. If you choose 'n' and would like to use
741 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
742 If unsure, say Y.
743
744 # need this always selected by IOMMU for the VIA workaround
745 config SWIOTLB
746 def_bool y if X86_64
747 ---help---
748 Support for software bounce buffers used on x86-64 systems
749 which don't have a hardware IOMMU. Using this PCI devices
750 which can only access 32-bits of memory can be used on systems
751 with more than 3 GB of memory.
752 If unsure, say Y.
753
754 config IOMMU_HELPER
755 def_bool y
756 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
757
758 config MAXSMP
759 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
760 depends on X86_64 && SMP && DEBUG_KERNEL
761 select CPUMASK_OFFSTACK
762 ---help---
763 Enable maximum number of CPUS and NUMA Nodes for this architecture.
764 If unsure, say N.
765
766 config NR_CPUS
767 int "Maximum number of CPUs" if SMP && !MAXSMP
768 range 2 8 if SMP && X86_32 && !X86_BIGSMP
769 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
770 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
771 default "1" if !SMP
772 default "8192" if MAXSMP
773 default "32" if SMP && X86_BIGSMP
774 default "8" if SMP
775 ---help---
776 This allows you to specify the maximum number of CPUs which this
777 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
778 supported value is 4096, otherwise the maximum value is 512. The
779 minimum value which makes sense is 2.
780
781 This is purely to save memory - each supported CPU adds
782 approximately eight kilobytes to the kernel image.
783
784 config SCHED_SMT
785 bool "SMT (Hyperthreading) scheduler support"
786 depends on X86_HT
787 ---help---
788 SMT scheduler support improves the CPU scheduler's decision making
789 when dealing with Intel Pentium 4 chips with HyperThreading at a
790 cost of slightly increased overhead in some places. If unsure say
791 N here.
792
793 config SCHED_MC
794 def_bool y
795 prompt "Multi-core scheduler support"
796 depends on X86_HT
797 ---help---
798 Multi-core scheduler support improves the CPU scheduler's decision
799 making when dealing with multi-core CPU chips at a cost of slightly
800 increased overhead in some places. If unsure say N here.
801
802 source "kernel/Kconfig.preempt"
803
804 config X86_UP_APIC
805 bool "Local APIC support on uniprocessors"
806 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
807 ---help---
808 A local APIC (Advanced Programmable Interrupt Controller) is an
809 integrated interrupt controller in the CPU. If you have a single-CPU
810 system which has a processor with a local APIC, you can say Y here to
811 enable and use it. If you say Y here even though your machine doesn't
812 have a local APIC, then the kernel will still run with no slowdown at
813 all. The local APIC supports CPU-generated self-interrupts (timer,
814 performance counters), and the NMI watchdog which detects hard
815 lockups.
816
817 config X86_UP_IOAPIC
818 bool "IO-APIC support on uniprocessors"
819 depends on X86_UP_APIC
820 ---help---
821 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
822 SMP-capable replacement for PC-style interrupt controllers. Most
823 SMP systems and many recent uniprocessor systems have one.
824
825 If you have a single-CPU system with an IO-APIC, you can say Y here
826 to use it. If you say Y here even though your machine doesn't have
827 an IO-APIC, then the kernel will still run with no slowdown at all.
828
829 config X86_LOCAL_APIC
830 def_bool y
831 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
832
833 config X86_IO_APIC
834 def_bool y
835 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
836
837 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
838 bool "Reroute for broken boot IRQs"
839 depends on X86_IO_APIC
840 ---help---
841 This option enables a workaround that fixes a source of
842 spurious interrupts. This is recommended when threaded
843 interrupt handling is used on systems where the generation of
844 superfluous "boot interrupts" cannot be disabled.
845
846 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
847 entry in the chipset's IO-APIC is masked (as, e.g. the RT
848 kernel does during interrupt handling). On chipsets where this
849 boot IRQ generation cannot be disabled, this workaround keeps
850 the original IRQ line masked so that only the equivalent "boot
851 IRQ" is delivered to the CPUs. The workaround also tells the
852 kernel to set up the IRQ handler on the boot IRQ line. In this
853 way only one interrupt is delivered to the kernel. Otherwise
854 the spurious second interrupt may cause the kernel to bring
855 down (vital) interrupt lines.
856
857 Only affects "broken" chipsets. Interrupt sharing may be
858 increased on these systems.
859
860 config X86_MCE
861 bool "Machine Check / overheating reporting"
862 default y
863 ---help---
864 Machine Check support allows the processor to notify the
865 kernel if it detects a problem (e.g. overheating, data corruption).
866 The action the kernel takes depends on the severity of the problem,
867 ranging from warning messages to halting the machine.
868
869 config X86_MCE_INTEL
870 def_bool y
871 prompt "Intel MCE features"
872 depends on X86_MCE && X86_LOCAL_APIC
873 ---help---
874 Additional support for intel specific MCE features such as
875 the thermal monitor.
876
877 config X86_MCE_AMD
878 def_bool y
879 prompt "AMD MCE features"
880 depends on X86_MCE && X86_LOCAL_APIC
881 ---help---
882 Additional support for AMD specific MCE features such as
883 the DRAM Error Threshold.
884
885 config X86_ANCIENT_MCE
886 bool "Support for old Pentium 5 / WinChip machine checks"
887 depends on X86_32 && X86_MCE
888 ---help---
889 Include support for machine check handling on old Pentium 5 or WinChip
890 systems. These typically need to be enabled explicitly on the command
891 line.
892
893 config X86_MCE_THRESHOLD
894 depends on X86_MCE_AMD || X86_MCE_INTEL
895 def_bool y
896
897 config X86_MCE_INJECT
898 depends on X86_MCE
899 tristate "Machine check injector support"
900 ---help---
901 Provide support for injecting machine checks for testing purposes.
902 If you don't know what a machine check is and you don't do kernel
903 QA it is safe to say n.
904
905 config X86_THERMAL_VECTOR
906 def_bool y
907 depends on X86_MCE_INTEL
908
909 config VM86
910 bool "Enable VM86 support" if EXPERT
911 default y
912 depends on X86_32
913 ---help---
914 This option is required by programs like DOSEMU to run 16-bit legacy
915 code on X86 processors. It also may be needed by software like
916 XFree86 to initialize some video cards via BIOS. Disabling this
917 option saves about 6k.
918
919 config TOSHIBA
920 tristate "Toshiba Laptop support"
921 depends on X86_32
922 ---help---
923 This adds a driver to safely access the System Management Mode of
924 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
925 not work on models with a Phoenix BIOS. The System Management Mode
926 is used to set the BIOS and power saving options on Toshiba portables.
927
928 For information on utilities to make use of this driver see the
929 Toshiba Linux utilities web site at:
930 <http://www.buzzard.org.uk/toshiba/>.
931
932 Say Y if you intend to run this kernel on a Toshiba portable.
933 Say N otherwise.
934
935 config I8K
936 tristate "Dell laptop support"
937 select HWMON
938 ---help---
939 This adds a driver to safely access the System Management Mode
940 of the CPU on the Dell Inspiron 8000. The System Management Mode
941 is used to read cpu temperature and cooling fan status and to
942 control the fans on the I8K portables.
943
944 This driver has been tested only on the Inspiron 8000 but it may
945 also work with other Dell laptops. You can force loading on other
946 models by passing the parameter `force=1' to the module. Use at
947 your own risk.
948
949 For information on utilities to make use of this driver see the
950 I8K Linux utilities web site at:
951 <http://people.debian.org/~dz/i8k/>
952
953 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
954 Say N otherwise.
955
956 config X86_REBOOTFIXUPS
957 bool "Enable X86 board specific fixups for reboot"
958 depends on X86_32
959 ---help---
960 This enables chipset and/or board specific fixups to be done
961 in order to get reboot to work correctly. This is only needed on
962 some combinations of hardware and BIOS. The symptom, for which
963 this config is intended, is when reboot ends with a stalled/hung
964 system.
965
966 Currently, the only fixup is for the Geode machines using
967 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
968
969 Say Y if you want to enable the fixup. Currently, it's safe to
970 enable this option even if you don't need it.
971 Say N otherwise.
972
973 config MICROCODE
974 tristate "CPU microcode loading support"
975 depends on CPU_SUP_AMD || CPU_SUP_INTEL
976 select FW_LOADER
977 ---help---
978
979 If you say Y here, you will be able to update the microcode on
980 certain Intel and AMD processors. The Intel support is for the
981 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
982 Xeon etc. The AMD support is for families 0x10 and later. You will
983 obviously need the actual microcode binary data itself which is not
984 shipped with the Linux kernel.
985
986 This option selects the general module only, you need to select
987 at least one vendor specific module as well.
988
989 To compile this driver as a module, choose M here: the module
990 will be called microcode.
991
992 config MICROCODE_INTEL
993 bool "Intel microcode loading support"
994 depends on MICROCODE
995 default MICROCODE
996 select FW_LOADER
997 ---help---
998 This options enables microcode patch loading support for Intel
999 processors.
1000
1001 For the current Intel microcode data package go to
1002 <https://downloadcenter.intel.com> and search for
1003 'Linux Processor Microcode Data File'.
1004
1005 config MICROCODE_AMD
1006 bool "AMD microcode loading support"
1007 depends on MICROCODE
1008 select FW_LOADER
1009 ---help---
1010 If you select this option, microcode patch loading support for AMD
1011 processors will be enabled.
1012
1013 config MICROCODE_OLD_INTERFACE
1014 def_bool y
1015 depends on MICROCODE
1016
1017 config MICROCODE_INTEL_EARLY
1018 def_bool n
1019
1020 config MICROCODE_AMD_EARLY
1021 def_bool n
1022
1023 config MICROCODE_EARLY
1024 bool "Early load microcode"
1025 depends on MICROCODE=y && BLK_DEV_INITRD
1026 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1027 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1028 default y
1029 help
1030 This option provides functionality to read additional microcode data
1031 at the beginning of initrd image. The data tells kernel to load
1032 microcode to CPU's as early as possible. No functional change if no
1033 microcode data is glued to the initrd, therefore it's safe to say Y.
1034
1035 config X86_MSR
1036 tristate "/dev/cpu/*/msr - Model-specific register support"
1037 ---help---
1038 This device gives privileged processes access to the x86
1039 Model-Specific Registers (MSRs). It is a character device with
1040 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1041 MSR accesses are directed to a specific CPU on multi-processor
1042 systems.
1043
1044 config X86_CPUID
1045 tristate "/dev/cpu/*/cpuid - CPU information support"
1046 ---help---
1047 This device gives processes access to the x86 CPUID instruction to
1048 be executed on a specific processor. It is a character device
1049 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1050 /dev/cpu/31/cpuid.
1051
1052 choice
1053 prompt "High Memory Support"
1054 default HIGHMEM4G
1055 depends on X86_32
1056
1057 config NOHIGHMEM
1058 bool "off"
1059 ---help---
1060 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1061 However, the address space of 32-bit x86 processors is only 4
1062 Gigabytes large. That means that, if you have a large amount of
1063 physical memory, not all of it can be "permanently mapped" by the
1064 kernel. The physical memory that's not permanently mapped is called
1065 "high memory".
1066
1067 If you are compiling a kernel which will never run on a machine with
1068 more than 1 Gigabyte total physical RAM, answer "off" here (default
1069 choice and suitable for most users). This will result in a "3GB/1GB"
1070 split: 3GB are mapped so that each process sees a 3GB virtual memory
1071 space and the remaining part of the 4GB virtual memory space is used
1072 by the kernel to permanently map as much physical memory as
1073 possible.
1074
1075 If the machine has between 1 and 4 Gigabytes physical RAM, then
1076 answer "4GB" here.
1077
1078 If more than 4 Gigabytes is used then answer "64GB" here. This
1079 selection turns Intel PAE (Physical Address Extension) mode on.
1080 PAE implements 3-level paging on IA32 processors. PAE is fully
1081 supported by Linux, PAE mode is implemented on all recent Intel
1082 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1083 then the kernel will not boot on CPUs that don't support PAE!
1084
1085 The actual amount of total physical memory will either be
1086 auto detected or can be forced by using a kernel command line option
1087 such as "mem=256M". (Try "man bootparam" or see the documentation of
1088 your boot loader (lilo or loadlin) about how to pass options to the
1089 kernel at boot time.)
1090
1091 If unsure, say "off".
1092
1093 config HIGHMEM4G
1094 bool "4GB"
1095 ---help---
1096 Select this if you have a 32-bit processor and between 1 and 4
1097 gigabytes of physical RAM.
1098
1099 config HIGHMEM64G
1100 bool "64GB"
1101 depends on !M486
1102 select X86_PAE
1103 ---help---
1104 Select this if you have a 32-bit processor and more than 4
1105 gigabytes of physical RAM.
1106
1107 endchoice
1108
1109 choice
1110 prompt "Memory split" if EXPERT
1111 default VMSPLIT_3G
1112 depends on X86_32
1113 ---help---
1114 Select the desired split between kernel and user memory.
1115
1116 If the address range available to the kernel is less than the
1117 physical memory installed, the remaining memory will be available
1118 as "high memory". Accessing high memory is a little more costly
1119 than low memory, as it needs to be mapped into the kernel first.
1120 Note that increasing the kernel address space limits the range
1121 available to user programs, making the address space there
1122 tighter. Selecting anything other than the default 3G/1G split
1123 will also likely make your kernel incompatible with binary-only
1124 kernel modules.
1125
1126 If you are not absolutely sure what you are doing, leave this
1127 option alone!
1128
1129 config VMSPLIT_3G
1130 bool "3G/1G user/kernel split"
1131 config VMSPLIT_3G_OPT
1132 depends on !X86_PAE
1133 bool "3G/1G user/kernel split (for full 1G low memory)"
1134 config VMSPLIT_2G
1135 bool "2G/2G user/kernel split"
1136 config VMSPLIT_2G_OPT
1137 depends on !X86_PAE
1138 bool "2G/2G user/kernel split (for full 2G low memory)"
1139 config VMSPLIT_1G
1140 bool "1G/3G user/kernel split"
1141 endchoice
1142
1143 config PAGE_OFFSET
1144 hex
1145 default 0xB0000000 if VMSPLIT_3G_OPT
1146 default 0x80000000 if VMSPLIT_2G
1147 default 0x78000000 if VMSPLIT_2G_OPT
1148 default 0x40000000 if VMSPLIT_1G
1149 default 0xC0000000
1150 depends on X86_32
1151
1152 config HIGHMEM
1153 def_bool y
1154 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1155
1156 config X86_PAE
1157 bool "PAE (Physical Address Extension) Support"
1158 depends on X86_32 && !HIGHMEM4G
1159 ---help---
1160 PAE is required for NX support, and furthermore enables
1161 larger swapspace support for non-overcommit purposes. It
1162 has the cost of more pagetable lookup overhead, and also
1163 consumes more pagetable space per process.
1164
1165 config ARCH_PHYS_ADDR_T_64BIT
1166 def_bool y
1167 depends on X86_64 || X86_PAE
1168
1169 config ARCH_DMA_ADDR_T_64BIT
1170 def_bool y
1171 depends on X86_64 || HIGHMEM64G
1172
1173 config DIRECT_GBPAGES
1174 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1175 default y
1176 depends on X86_64
1177 ---help---
1178 Allow the kernel linear mapping to use 1GB pages on CPUs that
1179 support it. This can improve the kernel's performance a tiny bit by
1180 reducing TLB pressure. If in doubt, say "Y".
1181
1182 # Common NUMA Features
1183 config NUMA
1184 bool "Numa Memory Allocation and Scheduler Support"
1185 depends on SMP
1186 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1187 default y if X86_BIGSMP
1188 ---help---
1189 Enable NUMA (Non Uniform Memory Access) support.
1190
1191 The kernel will try to allocate memory used by a CPU on the
1192 local memory controller of the CPU and add some more
1193 NUMA awareness to the kernel.
1194
1195 For 64-bit this is recommended if the system is Intel Core i7
1196 (or later), AMD Opteron, or EM64T NUMA.
1197
1198 For 32-bit this is only needed if you boot a 32-bit
1199 kernel on a 64-bit NUMA platform.
1200
1201 Otherwise, you should say N.
1202
1203 config AMD_NUMA
1204 def_bool y
1205 prompt "Old style AMD Opteron NUMA detection"
1206 depends on X86_64 && NUMA && PCI
1207 ---help---
1208 Enable AMD NUMA node topology detection. You should say Y here if
1209 you have a multi processor AMD system. This uses an old method to
1210 read the NUMA configuration directly from the builtin Northbridge
1211 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1212 which also takes priority if both are compiled in.
1213
1214 config X86_64_ACPI_NUMA
1215 def_bool y
1216 prompt "ACPI NUMA detection"
1217 depends on X86_64 && NUMA && ACPI && PCI
1218 select ACPI_NUMA
1219 ---help---
1220 Enable ACPI SRAT based node topology detection.
1221
1222 # Some NUMA nodes have memory ranges that span
1223 # other nodes. Even though a pfn is valid and
1224 # between a node's start and end pfns, it may not
1225 # reside on that node. See memmap_init_zone()
1226 # for details.
1227 config NODES_SPAN_OTHER_NODES
1228 def_bool y
1229 depends on X86_64_ACPI_NUMA
1230
1231 config NUMA_EMU
1232 bool "NUMA emulation"
1233 depends on NUMA
1234 ---help---
1235 Enable NUMA emulation. A flat machine will be split
1236 into virtual nodes when booted with "numa=fake=N", where N is the
1237 number of nodes. This is only useful for debugging.
1238
1239 config NODES_SHIFT
1240 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1241 range 1 10
1242 default "10" if MAXSMP
1243 default "6" if X86_64
1244 default "3"
1245 depends on NEED_MULTIPLE_NODES
1246 ---help---
1247 Specify the maximum number of NUMA Nodes available on the target
1248 system. Increases memory reserved to accommodate various tables.
1249
1250 config ARCH_HAVE_MEMORY_PRESENT
1251 def_bool y
1252 depends on X86_32 && DISCONTIGMEM
1253
1254 config NEED_NODE_MEMMAP_SIZE
1255 def_bool y
1256 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1257
1258 config ARCH_FLATMEM_ENABLE
1259 def_bool y
1260 depends on X86_32 && !NUMA
1261
1262 config ARCH_DISCONTIGMEM_ENABLE
1263 def_bool y
1264 depends on NUMA && X86_32
1265
1266 config ARCH_DISCONTIGMEM_DEFAULT
1267 def_bool y
1268 depends on NUMA && X86_32
1269
1270 config ARCH_SPARSEMEM_ENABLE
1271 def_bool y
1272 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1273 select SPARSEMEM_STATIC if X86_32
1274 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1275
1276 config ARCH_SPARSEMEM_DEFAULT
1277 def_bool y
1278 depends on X86_64
1279
1280 config ARCH_SELECT_MEMORY_MODEL
1281 def_bool y
1282 depends on ARCH_SPARSEMEM_ENABLE
1283
1284 config ARCH_MEMORY_PROBE
1285 bool "Enable sysfs memory/probe interface"
1286 depends on X86_64 && MEMORY_HOTPLUG
1287 help
1288 This option enables a sysfs memory/probe interface for testing.
1289 See Documentation/memory-hotplug.txt for more information.
1290 If you are unsure how to answer this question, answer N.
1291
1292 config ARCH_PROC_KCORE_TEXT
1293 def_bool y
1294 depends on X86_64 && PROC_KCORE
1295
1296 config ILLEGAL_POINTER_VALUE
1297 hex
1298 default 0 if X86_32
1299 default 0xdead000000000000 if X86_64
1300
1301 source "mm/Kconfig"
1302
1303 config HIGHPTE
1304 bool "Allocate 3rd-level pagetables from highmem"
1305 depends on HIGHMEM
1306 ---help---
1307 The VM uses one page table entry for each page of physical memory.
1308 For systems with a lot of RAM, this can be wasteful of precious
1309 low memory. Setting this option will put user-space page table
1310 entries in high memory.
1311
1312 config X86_CHECK_BIOS_CORRUPTION
1313 bool "Check for low memory corruption"
1314 ---help---
1315 Periodically check for memory corruption in low memory, which
1316 is suspected to be caused by BIOS. Even when enabled in the
1317 configuration, it is disabled at runtime. Enable it by
1318 setting "memory_corruption_check=1" on the kernel command
1319 line. By default it scans the low 64k of memory every 60
1320 seconds; see the memory_corruption_check_size and
1321 memory_corruption_check_period parameters in
1322 Documentation/kernel-parameters.txt to adjust this.
1323
1324 When enabled with the default parameters, this option has
1325 almost no overhead, as it reserves a relatively small amount
1326 of memory and scans it infrequently. It both detects corruption
1327 and prevents it from affecting the running system.
1328
1329 It is, however, intended as a diagnostic tool; if repeatable
1330 BIOS-originated corruption always affects the same memory,
1331 you can use memmap= to prevent the kernel from using that
1332 memory.
1333
1334 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1335 bool "Set the default setting of memory_corruption_check"
1336 depends on X86_CHECK_BIOS_CORRUPTION
1337 default y
1338 ---help---
1339 Set whether the default state of memory_corruption_check is
1340 on or off.
1341
1342 config X86_RESERVE_LOW
1343 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1344 default 64
1345 range 4 640
1346 ---help---
1347 Specify the amount of low memory to reserve for the BIOS.
1348
1349 The first page contains BIOS data structures that the kernel
1350 must not use, so that page must always be reserved.
1351
1352 By default we reserve the first 64K of physical RAM, as a
1353 number of BIOSes are known to corrupt that memory range
1354 during events such as suspend/resume or monitor cable
1355 insertion, so it must not be used by the kernel.
1356
1357 You can set this to 4 if you are absolutely sure that you
1358 trust the BIOS to get all its memory reservations and usages
1359 right. If you know your BIOS have problems beyond the
1360 default 64K area, you can set this to 640 to avoid using the
1361 entire low memory range.
1362
1363 If you have doubts about the BIOS (e.g. suspend/resume does
1364 not work or there's kernel crashes after certain hardware
1365 hotplug events) then you might want to enable
1366 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1367 typical corruption patterns.
1368
1369 Leave this to the default value of 64 if you are unsure.
1370
1371 config MATH_EMULATION
1372 bool
1373 prompt "Math emulation" if X86_32
1374 ---help---
1375 Linux can emulate a math coprocessor (used for floating point
1376 operations) if you don't have one. 486DX and Pentium processors have
1377 a math coprocessor built in, 486SX and 386 do not, unless you added
1378 a 487DX or 387, respectively. (The messages during boot time can
1379 give you some hints here ["man dmesg"].) Everyone needs either a
1380 coprocessor or this emulation.
1381
1382 If you don't have a math coprocessor, you need to say Y here; if you
1383 say Y here even though you have a coprocessor, the coprocessor will
1384 be used nevertheless. (This behavior can be changed with the kernel
1385 command line option "no387", which comes handy if your coprocessor
1386 is broken. Try "man bootparam" or see the documentation of your boot
1387 loader (lilo or loadlin) about how to pass options to the kernel at
1388 boot time.) This means that it is a good idea to say Y here if you
1389 intend to use this kernel on different machines.
1390
1391 More information about the internals of the Linux math coprocessor
1392 emulation can be found in <file:arch/x86/math-emu/README>.
1393
1394 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1395 kernel, it won't hurt.
1396
1397 config MTRR
1398 def_bool y
1399 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1400 ---help---
1401 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1402 the Memory Type Range Registers (MTRRs) may be used to control
1403 processor access to memory ranges. This is most useful if you have
1404 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1405 allows bus write transfers to be combined into a larger transfer
1406 before bursting over the PCI/AGP bus. This can increase performance
1407 of image write operations 2.5 times or more. Saying Y here creates a
1408 /proc/mtrr file which may be used to manipulate your processor's
1409 MTRRs. Typically the X server should use this.
1410
1411 This code has a reasonably generic interface so that similar
1412 control registers on other processors can be easily supported
1413 as well:
1414
1415 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1416 Registers (ARRs) which provide a similar functionality to MTRRs. For
1417 these, the ARRs are used to emulate the MTRRs.
1418 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1419 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1420 write-combining. All of these processors are supported by this code
1421 and it makes sense to say Y here if you have one of them.
1422
1423 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1424 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1425 can lead to all sorts of problems, so it's good to say Y here.
1426
1427 You can safely say Y even if your machine doesn't have MTRRs, you'll
1428 just add about 9 KB to your kernel.
1429
1430 See <file:Documentation/x86/mtrr.txt> for more information.
1431
1432 config MTRR_SANITIZER
1433 def_bool y
1434 prompt "MTRR cleanup support"
1435 depends on MTRR
1436 ---help---
1437 Convert MTRR layout from continuous to discrete, so X drivers can
1438 add writeback entries.
1439
1440 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1441 The largest mtrr entry size for a continuous block can be set with
1442 mtrr_chunk_size.
1443
1444 If unsure, say Y.
1445
1446 config MTRR_SANITIZER_ENABLE_DEFAULT
1447 int "MTRR cleanup enable value (0-1)"
1448 range 0 1
1449 default "0"
1450 depends on MTRR_SANITIZER
1451 ---help---
1452 Enable mtrr cleanup default value
1453
1454 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1455 int "MTRR cleanup spare reg num (0-7)"
1456 range 0 7
1457 default "1"
1458 depends on MTRR_SANITIZER
1459 ---help---
1460 mtrr cleanup spare entries default, it can be changed via
1461 mtrr_spare_reg_nr=N on the kernel command line.
1462
1463 config X86_PAT
1464 def_bool y
1465 prompt "x86 PAT support" if EXPERT
1466 depends on MTRR
1467 ---help---
1468 Use PAT attributes to setup page level cache control.
1469
1470 PATs are the modern equivalents of MTRRs and are much more
1471 flexible than MTRRs.
1472
1473 Say N here if you see bootup problems (boot crash, boot hang,
1474 spontaneous reboots) or a non-working video driver.
1475
1476 If unsure, say Y.
1477
1478 config ARCH_USES_PG_UNCACHED
1479 def_bool y
1480 depends on X86_PAT
1481
1482 config ARCH_RANDOM
1483 def_bool y
1484 prompt "x86 architectural random number generator" if EXPERT
1485 ---help---
1486 Enable the x86 architectural RDRAND instruction
1487 (Intel Bull Mountain technology) to generate random numbers.
1488 If supported, this is a high bandwidth, cryptographically
1489 secure hardware random number generator.
1490
1491 config X86_SMAP
1492 def_bool y
1493 prompt "Supervisor Mode Access Prevention" if EXPERT
1494 ---help---
1495 Supervisor Mode Access Prevention (SMAP) is a security
1496 feature in newer Intel processors. There is a small
1497 performance cost if this enabled and turned on; there is
1498 also a small increase in the kernel size if this is enabled.
1499
1500 If unsure, say Y.
1501
1502 config EFI
1503 bool "EFI runtime service support"
1504 depends on ACPI
1505 select UCS2_STRING
1506 ---help---
1507 This enables the kernel to use EFI runtime services that are
1508 available (such as the EFI variable services).
1509
1510 This option is only useful on systems that have EFI firmware.
1511 In addition, you should use the latest ELILO loader available
1512 at <http://elilo.sourceforge.net> in order to take advantage
1513 of EFI runtime services. However, even with this option, the
1514 resultant kernel should continue to boot on existing non-EFI
1515 platforms.
1516
1517 config EFI_STUB
1518 bool "EFI stub support"
1519 depends on EFI
1520 ---help---
1521 This kernel feature allows a bzImage to be loaded directly
1522 by EFI firmware without the use of a bootloader.
1523
1524 See Documentation/efi-stub.txt for more information.
1525
1526 config EFI_MIXED
1527 bool "EFI mixed-mode support"
1528 depends on EFI_STUB && X86_64
1529 ---help---
1530 Enabling this feature allows a 64-bit kernel to be booted
1531 on a 32-bit firmware, provided that your CPU supports 64-bit
1532 mode.
1533
1534 Note that it is not possible to boot a mixed-mode enabled
1535 kernel via the EFI boot stub - a bootloader that supports
1536 the EFI handover protocol must be used.
1537
1538 If unsure, say N.
1539
1540 config SECCOMP
1541 def_bool y
1542 prompt "Enable seccomp to safely compute untrusted bytecode"
1543 ---help---
1544 This kernel feature is useful for number crunching applications
1545 that may need to compute untrusted bytecode during their
1546 execution. By using pipes or other transports made available to
1547 the process as file descriptors supporting the read/write
1548 syscalls, it's possible to isolate those applications in
1549 their own address space using seccomp. Once seccomp is
1550 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1551 and the task is only allowed to execute a few safe syscalls
1552 defined by each seccomp mode.
1553
1554 If unsure, say Y. Only embedded should say N here.
1555
1556 source kernel/Kconfig.hz
1557
1558 config KEXEC
1559 bool "kexec system call"
1560 ---help---
1561 kexec is a system call that implements the ability to shutdown your
1562 current kernel, and to start another kernel. It is like a reboot
1563 but it is independent of the system firmware. And like a reboot
1564 you can start any kernel with it, not just Linux.
1565
1566 The name comes from the similarity to the exec system call.
1567
1568 It is an ongoing process to be certain the hardware in a machine
1569 is properly shutdown, so do not be surprised if this code does not
1570 initially work for you. As of this writing the exact hardware
1571 interface is strongly in flux, so no good recommendation can be
1572 made.
1573
1574 config CRASH_DUMP
1575 bool "kernel crash dumps"
1576 depends on X86_64 || (X86_32 && HIGHMEM)
1577 ---help---
1578 Generate crash dump after being started by kexec.
1579 This should be normally only set in special crash dump kernels
1580 which are loaded in the main kernel with kexec-tools into
1581 a specially reserved region and then later executed after
1582 a crash by kdump/kexec. The crash dump kernel must be compiled
1583 to a memory address not used by the main kernel or BIOS using
1584 PHYSICAL_START, or it must be built as a relocatable image
1585 (CONFIG_RELOCATABLE=y).
1586 For more details see Documentation/kdump/kdump.txt
1587
1588 config KEXEC_JUMP
1589 bool "kexec jump"
1590 depends on KEXEC && HIBERNATION
1591 ---help---
1592 Jump between original kernel and kexeced kernel and invoke
1593 code in physical address mode via KEXEC
1594
1595 config PHYSICAL_START
1596 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1597 default "0x1000000"
1598 ---help---
1599 This gives the physical address where the kernel is loaded.
1600
1601 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1602 bzImage will decompress itself to above physical address and
1603 run from there. Otherwise, bzImage will run from the address where
1604 it has been loaded by the boot loader and will ignore above physical
1605 address.
1606
1607 In normal kdump cases one does not have to set/change this option
1608 as now bzImage can be compiled as a completely relocatable image
1609 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1610 address. This option is mainly useful for the folks who don't want
1611 to use a bzImage for capturing the crash dump and want to use a
1612 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1613 to be specifically compiled to run from a specific memory area
1614 (normally a reserved region) and this option comes handy.
1615
1616 So if you are using bzImage for capturing the crash dump,
1617 leave the value here unchanged to 0x1000000 and set
1618 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1619 for capturing the crash dump change this value to start of
1620 the reserved region. In other words, it can be set based on
1621 the "X" value as specified in the "crashkernel=YM@XM"
1622 command line boot parameter passed to the panic-ed
1623 kernel. Please take a look at Documentation/kdump/kdump.txt
1624 for more details about crash dumps.
1625
1626 Usage of bzImage for capturing the crash dump is recommended as
1627 one does not have to build two kernels. Same kernel can be used
1628 as production kernel and capture kernel. Above option should have
1629 gone away after relocatable bzImage support is introduced. But it
1630 is present because there are users out there who continue to use
1631 vmlinux for dump capture. This option should go away down the
1632 line.
1633
1634 Don't change this unless you know what you are doing.
1635
1636 config RELOCATABLE
1637 bool "Build a relocatable kernel"
1638 default y
1639 ---help---
1640 This builds a kernel image that retains relocation information
1641 so it can be loaded someplace besides the default 1MB.
1642 The relocations tend to make the kernel binary about 10% larger,
1643 but are discarded at runtime.
1644
1645 One use is for the kexec on panic case where the recovery kernel
1646 must live at a different physical address than the primary
1647 kernel.
1648
1649 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1650 it has been loaded at and the compile time physical address
1651 (CONFIG_PHYSICAL_START) is used as the minimum location.
1652
1653 config RANDOMIZE_BASE
1654 bool "Randomize the address of the kernel image"
1655 depends on RELOCATABLE
1656 depends on !HIBERNATION
1657 default n
1658 ---help---
1659 Randomizes the physical and virtual address at which the
1660 kernel image is decompressed, as a security feature that
1661 deters exploit attempts relying on knowledge of the location
1662 of kernel internals.
1663
1664 Entropy is generated using the RDRAND instruction if it is
1665 supported. If RDTSC is supported, it is used as well. If
1666 neither RDRAND nor RDTSC are supported, then randomness is
1667 read from the i8254 timer.
1668
1669 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1670 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1671 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1672 minimum of 2MiB, only 10 bits of entropy is theoretically
1673 possible. At best, due to page table layouts, 64-bit can use
1674 9 bits of entropy and 32-bit uses 8 bits.
1675
1676 If unsure, say N.
1677
1678 config RANDOMIZE_BASE_MAX_OFFSET
1679 hex "Maximum kASLR offset allowed" if EXPERT
1680 depends on RANDOMIZE_BASE
1681 range 0x0 0x20000000 if X86_32
1682 default "0x20000000" if X86_32
1683 range 0x0 0x40000000 if X86_64
1684 default "0x40000000" if X86_64
1685 ---help---
1686 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1687 memory is used to determine the maximal offset in bytes that will
1688 be applied to the kernel when kernel Address Space Layout
1689 Randomization (kASLR) is active. This must be a multiple of
1690 PHYSICAL_ALIGN.
1691
1692 On 32-bit this is limited to 512MiB by page table layouts. The
1693 default is 512MiB.
1694
1695 On 64-bit this is limited by how the kernel fixmap page table is
1696 positioned, so this cannot be larger than 1GiB currently. Without
1697 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1698 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1699 modules area will shrink to compensate, up to the current maximum
1700 1GiB to 1GiB split. The default is 1GiB.
1701
1702 If unsure, leave at the default value.
1703
1704 # Relocation on x86 needs some additional build support
1705 config X86_NEED_RELOCS
1706 def_bool y
1707 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1708
1709 config PHYSICAL_ALIGN
1710 hex "Alignment value to which kernel should be aligned"
1711 default "0x200000"
1712 range 0x2000 0x1000000 if X86_32
1713 range 0x200000 0x1000000 if X86_64
1714 ---help---
1715 This value puts the alignment restrictions on physical address
1716 where kernel is loaded and run from. Kernel is compiled for an
1717 address which meets above alignment restriction.
1718
1719 If bootloader loads the kernel at a non-aligned address and
1720 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1721 address aligned to above value and run from there.
1722
1723 If bootloader loads the kernel at a non-aligned address and
1724 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1725 load address and decompress itself to the address it has been
1726 compiled for and run from there. The address for which kernel is
1727 compiled already meets above alignment restrictions. Hence the
1728 end result is that kernel runs from a physical address meeting
1729 above alignment restrictions.
1730
1731 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1732 this value must be a multiple of 0x200000.
1733
1734 Don't change this unless you know what you are doing.
1735
1736 config HOTPLUG_CPU
1737 bool "Support for hot-pluggable CPUs"
1738 depends on SMP
1739 ---help---
1740 Say Y here to allow turning CPUs off and on. CPUs can be
1741 controlled through /sys/devices/system/cpu.
1742 ( Note: power management support will enable this option
1743 automatically on SMP systems. )
1744 Say N if you want to disable CPU hotplug.
1745
1746 config BOOTPARAM_HOTPLUG_CPU0
1747 bool "Set default setting of cpu0_hotpluggable"
1748 default n
1749 depends on HOTPLUG_CPU
1750 ---help---
1751 Set whether default state of cpu0_hotpluggable is on or off.
1752
1753 Say Y here to enable CPU0 hotplug by default. If this switch
1754 is turned on, there is no need to give cpu0_hotplug kernel
1755 parameter and the CPU0 hotplug feature is enabled by default.
1756
1757 Please note: there are two known CPU0 dependencies if you want
1758 to enable the CPU0 hotplug feature either by this switch or by
1759 cpu0_hotplug kernel parameter.
1760
1761 First, resume from hibernate or suspend always starts from CPU0.
1762 So hibernate and suspend are prevented if CPU0 is offline.
1763
1764 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1765 offline if any interrupt can not migrate out of CPU0. There may
1766 be other CPU0 dependencies.
1767
1768 Please make sure the dependencies are under your control before
1769 you enable this feature.
1770
1771 Say N if you don't want to enable CPU0 hotplug feature by default.
1772 You still can enable the CPU0 hotplug feature at boot by kernel
1773 parameter cpu0_hotplug.
1774
1775 config DEBUG_HOTPLUG_CPU0
1776 def_bool n
1777 prompt "Debug CPU0 hotplug"
1778 depends on HOTPLUG_CPU
1779 ---help---
1780 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1781 soon as possible and boots up userspace with CPU0 offlined. User
1782 can online CPU0 back after boot time.
1783
1784 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1785 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1786 compilation or giving cpu0_hotplug kernel parameter at boot.
1787
1788 If unsure, say N.
1789
1790 config COMPAT_VDSO
1791 def_bool n
1792 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1793 depends on X86_32 || IA32_EMULATION
1794 ---help---
1795 Certain buggy versions of glibc will crash if they are
1796 presented with a 32-bit vDSO that is not mapped at the address
1797 indicated in its segment table.
1798
1799 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1800 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1801 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1802 the only released version with the bug, but OpenSUSE 9
1803 contains a buggy "glibc 2.3.2".
1804
1805 The symptom of the bug is that everything crashes on startup, saying:
1806 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1807
1808 Saying Y here changes the default value of the vdso32 boot
1809 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1810 This works around the glibc bug but hurts performance.
1811
1812 If unsure, say N: if you are compiling your own kernel, you
1813 are unlikely to be using a buggy version of glibc.
1814
1815 config CMDLINE_BOOL
1816 bool "Built-in kernel command line"
1817 ---help---
1818 Allow for specifying boot arguments to the kernel at
1819 build time. On some systems (e.g. embedded ones), it is
1820 necessary or convenient to provide some or all of the
1821 kernel boot arguments with the kernel itself (that is,
1822 to not rely on the boot loader to provide them.)
1823
1824 To compile command line arguments into the kernel,
1825 set this option to 'Y', then fill in the
1826 the boot arguments in CONFIG_CMDLINE.
1827
1828 Systems with fully functional boot loaders (i.e. non-embedded)
1829 should leave this option set to 'N'.
1830
1831 config CMDLINE
1832 string "Built-in kernel command string"
1833 depends on CMDLINE_BOOL
1834 default ""
1835 ---help---
1836 Enter arguments here that should be compiled into the kernel
1837 image and used at boot time. If the boot loader provides a
1838 command line at boot time, it is appended to this string to
1839 form the full kernel command line, when the system boots.
1840
1841 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1842 change this behavior.
1843
1844 In most cases, the command line (whether built-in or provided
1845 by the boot loader) should specify the device for the root
1846 file system.
1847
1848 config CMDLINE_OVERRIDE
1849 bool "Built-in command line overrides boot loader arguments"
1850 depends on CMDLINE_BOOL
1851 ---help---
1852 Set this option to 'Y' to have the kernel ignore the boot loader
1853 command line, and use ONLY the built-in command line.
1854
1855 This is used to work around broken boot loaders. This should
1856 be set to 'N' under normal conditions.
1857
1858 endmenu
1859
1860 config ARCH_ENABLE_MEMORY_HOTPLUG
1861 def_bool y
1862 depends on X86_64 || (X86_32 && HIGHMEM)
1863
1864 config ARCH_ENABLE_MEMORY_HOTREMOVE
1865 def_bool y
1866 depends on MEMORY_HOTPLUG
1867
1868 config USE_PERCPU_NUMA_NODE_ID
1869 def_bool y
1870 depends on NUMA
1871
1872 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1873 def_bool y
1874 depends on X86_64 || X86_PAE
1875
1876 menu "Power management and ACPI options"
1877
1878 config ARCH_HIBERNATION_HEADER
1879 def_bool y
1880 depends on X86_64 && HIBERNATION
1881
1882 source "kernel/power/Kconfig"
1883
1884 source "drivers/acpi/Kconfig"
1885
1886 source "drivers/sfi/Kconfig"
1887
1888 config X86_APM_BOOT
1889 def_bool y
1890 depends on APM
1891
1892 menuconfig APM
1893 tristate "APM (Advanced Power Management) BIOS support"
1894 depends on X86_32 && PM_SLEEP
1895 ---help---
1896 APM is a BIOS specification for saving power using several different
1897 techniques. This is mostly useful for battery powered laptops with
1898 APM compliant BIOSes. If you say Y here, the system time will be
1899 reset after a RESUME operation, the /proc/apm device will provide
1900 battery status information, and user-space programs will receive
1901 notification of APM "events" (e.g. battery status change).
1902
1903 If you select "Y" here, you can disable actual use of the APM
1904 BIOS by passing the "apm=off" option to the kernel at boot time.
1905
1906 Note that the APM support is almost completely disabled for
1907 machines with more than one CPU.
1908
1909 In order to use APM, you will need supporting software. For location
1910 and more information, read <file:Documentation/power/apm-acpi.txt>
1911 and the Battery Powered Linux mini-HOWTO, available from
1912 <http://www.tldp.org/docs.html#howto>.
1913
1914 This driver does not spin down disk drives (see the hdparm(8)
1915 manpage ("man 8 hdparm") for that), and it doesn't turn off
1916 VESA-compliant "green" monitors.
1917
1918 This driver does not support the TI 4000M TravelMate and the ACER
1919 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1920 desktop machines also don't have compliant BIOSes, and this driver
1921 may cause those machines to panic during the boot phase.
1922
1923 Generally, if you don't have a battery in your machine, there isn't
1924 much point in using this driver and you should say N. If you get
1925 random kernel OOPSes or reboots that don't seem to be related to
1926 anything, try disabling/enabling this option (or disabling/enabling
1927 APM in your BIOS).
1928
1929 Some other things you should try when experiencing seemingly random,
1930 "weird" problems:
1931
1932 1) make sure that you have enough swap space and that it is
1933 enabled.
1934 2) pass the "no-hlt" option to the kernel
1935 3) switch on floating point emulation in the kernel and pass
1936 the "no387" option to the kernel
1937 4) pass the "floppy=nodma" option to the kernel
1938 5) pass the "mem=4M" option to the kernel (thereby disabling
1939 all but the first 4 MB of RAM)
1940 6) make sure that the CPU is not over clocked.
1941 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1942 8) disable the cache from your BIOS settings
1943 9) install a fan for the video card or exchange video RAM
1944 10) install a better fan for the CPU
1945 11) exchange RAM chips
1946 12) exchange the motherboard.
1947
1948 To compile this driver as a module, choose M here: the
1949 module will be called apm.
1950
1951 if APM
1952
1953 config APM_IGNORE_USER_SUSPEND
1954 bool "Ignore USER SUSPEND"
1955 ---help---
1956 This option will ignore USER SUSPEND requests. On machines with a
1957 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1958 series notebooks, it is necessary to say Y because of a BIOS bug.
1959
1960 config APM_DO_ENABLE
1961 bool "Enable PM at boot time"
1962 ---help---
1963 Enable APM features at boot time. From page 36 of the APM BIOS
1964 specification: "When disabled, the APM BIOS does not automatically
1965 power manage devices, enter the Standby State, enter the Suspend
1966 State, or take power saving steps in response to CPU Idle calls."
1967 This driver will make CPU Idle calls when Linux is idle (unless this
1968 feature is turned off -- see "Do CPU IDLE calls", below). This
1969 should always save battery power, but more complicated APM features
1970 will be dependent on your BIOS implementation. You may need to turn
1971 this option off if your computer hangs at boot time when using APM
1972 support, or if it beeps continuously instead of suspending. Turn
1973 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1974 T400CDT. This is off by default since most machines do fine without
1975 this feature.
1976
1977 config APM_CPU_IDLE
1978 depends on CPU_IDLE
1979 bool "Make CPU Idle calls when idle"
1980 ---help---
1981 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1982 On some machines, this can activate improved power savings, such as
1983 a slowed CPU clock rate, when the machine is idle. These idle calls
1984 are made after the idle loop has run for some length of time (e.g.,
1985 333 mS). On some machines, this will cause a hang at boot time or
1986 whenever the CPU becomes idle. (On machines with more than one CPU,
1987 this option does nothing.)
1988
1989 config APM_DISPLAY_BLANK
1990 bool "Enable console blanking using APM"
1991 ---help---
1992 Enable console blanking using the APM. Some laptops can use this to
1993 turn off the LCD backlight when the screen blanker of the Linux
1994 virtual console blanks the screen. Note that this is only used by
1995 the virtual console screen blanker, and won't turn off the backlight
1996 when using the X Window system. This also doesn't have anything to
1997 do with your VESA-compliant power-saving monitor. Further, this
1998 option doesn't work for all laptops -- it might not turn off your
1999 backlight at all, or it might print a lot of errors to the console,
2000 especially if you are using gpm.
2001
2002 config APM_ALLOW_INTS
2003 bool "Allow interrupts during APM BIOS calls"
2004 ---help---
2005 Normally we disable external interrupts while we are making calls to
2006 the APM BIOS as a measure to lessen the effects of a badly behaving
2007 BIOS implementation. The BIOS should reenable interrupts if it
2008 needs to. Unfortunately, some BIOSes do not -- especially those in
2009 many of the newer IBM Thinkpads. If you experience hangs when you
2010 suspend, try setting this to Y. Otherwise, say N.
2011
2012 endif # APM
2013
2014 source "drivers/cpufreq/Kconfig"
2015
2016 source "drivers/cpuidle/Kconfig"
2017
2018 source "drivers/idle/Kconfig"
2019
2020 endmenu
2021
2022
2023 menu "Bus options (PCI etc.)"
2024
2025 config PCI
2026 bool "PCI support"
2027 default y
2028 ---help---
2029 Find out whether you have a PCI motherboard. PCI is the name of a
2030 bus system, i.e. the way the CPU talks to the other stuff inside
2031 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2032 VESA. If you have PCI, say Y, otherwise N.
2033
2034 choice
2035 prompt "PCI access mode"
2036 depends on X86_32 && PCI
2037 default PCI_GOANY
2038 ---help---
2039 On PCI systems, the BIOS can be used to detect the PCI devices and
2040 determine their configuration. However, some old PCI motherboards
2041 have BIOS bugs and may crash if this is done. Also, some embedded
2042 PCI-based systems don't have any BIOS at all. Linux can also try to
2043 detect the PCI hardware directly without using the BIOS.
2044
2045 With this option, you can specify how Linux should detect the
2046 PCI devices. If you choose "BIOS", the BIOS will be used,
2047 if you choose "Direct", the BIOS won't be used, and if you
2048 choose "MMConfig", then PCI Express MMCONFIG will be used.
2049 If you choose "Any", the kernel will try MMCONFIG, then the
2050 direct access method and falls back to the BIOS if that doesn't
2051 work. If unsure, go with the default, which is "Any".
2052
2053 config PCI_GOBIOS
2054 bool "BIOS"
2055
2056 config PCI_GOMMCONFIG
2057 bool "MMConfig"
2058
2059 config PCI_GODIRECT
2060 bool "Direct"
2061
2062 config PCI_GOOLPC
2063 bool "OLPC XO-1"
2064 depends on OLPC
2065
2066 config PCI_GOANY
2067 bool "Any"
2068
2069 endchoice
2070
2071 config PCI_BIOS
2072 def_bool y
2073 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2074
2075 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2076 config PCI_DIRECT
2077 def_bool y
2078 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2079
2080 config PCI_MMCONFIG
2081 def_bool y
2082 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2083
2084 config PCI_OLPC
2085 def_bool y
2086 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2087
2088 config PCI_XEN
2089 def_bool y
2090 depends on PCI && XEN
2091 select SWIOTLB_XEN
2092
2093 config PCI_DOMAINS
2094 def_bool y
2095 depends on PCI
2096
2097 config PCI_MMCONFIG
2098 bool "Support mmconfig PCI config space access"
2099 depends on X86_64 && PCI && ACPI
2100
2101 config PCI_CNB20LE_QUIRK
2102 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2103 depends on PCI
2104 help
2105 Read the PCI windows out of the CNB20LE host bridge. This allows
2106 PCI hotplug to work on systems with the CNB20LE chipset which do
2107 not have ACPI.
2108
2109 There's no public spec for this chipset, and this functionality
2110 is known to be incomplete.
2111
2112 You should say N unless you know you need this.
2113
2114 source "drivers/pci/pcie/Kconfig"
2115
2116 source "drivers/pci/Kconfig"
2117
2118 # x86_64 have no ISA slots, but can have ISA-style DMA.
2119 config ISA_DMA_API
2120 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2121 default y
2122 help
2123 Enables ISA-style DMA support for devices requiring such controllers.
2124 If unsure, say Y.
2125
2126 if X86_32
2127
2128 config ISA
2129 bool "ISA support"
2130 ---help---
2131 Find out whether you have ISA slots on your motherboard. ISA is the
2132 name of a bus system, i.e. the way the CPU talks to the other stuff
2133 inside your box. Other bus systems are PCI, EISA, MicroChannel
2134 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2135 newer boards don't support it. If you have ISA, say Y, otherwise N.
2136
2137 config EISA
2138 bool "EISA support"
2139 depends on ISA
2140 ---help---
2141 The Extended Industry Standard Architecture (EISA) bus was
2142 developed as an open alternative to the IBM MicroChannel bus.
2143
2144 The EISA bus provided some of the features of the IBM MicroChannel
2145 bus while maintaining backward compatibility with cards made for
2146 the older ISA bus. The EISA bus saw limited use between 1988 and
2147 1995 when it was made obsolete by the PCI bus.
2148
2149 Say Y here if you are building a kernel for an EISA-based machine.
2150
2151 Otherwise, say N.
2152
2153 source "drivers/eisa/Kconfig"
2154
2155 config SCx200
2156 tristate "NatSemi SCx200 support"
2157 ---help---
2158 This provides basic support for National Semiconductor's
2159 (now AMD's) Geode processors. The driver probes for the
2160 PCI-IDs of several on-chip devices, so its a good dependency
2161 for other scx200_* drivers.
2162
2163 If compiled as a module, the driver is named scx200.
2164
2165 config SCx200HR_TIMER
2166 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2167 depends on SCx200
2168 default y
2169 ---help---
2170 This driver provides a clocksource built upon the on-chip
2171 27MHz high-resolution timer. Its also a workaround for
2172 NSC Geode SC-1100's buggy TSC, which loses time when the
2173 processor goes idle (as is done by the scheduler). The
2174 other workaround is idle=poll boot option.
2175
2176 config OLPC
2177 bool "One Laptop Per Child support"
2178 depends on !X86_PAE
2179 select GPIOLIB
2180 select OF
2181 select OF_PROMTREE
2182 select IRQ_DOMAIN
2183 ---help---
2184 Add support for detecting the unique features of the OLPC
2185 XO hardware.
2186
2187 config OLPC_XO1_PM
2188 bool "OLPC XO-1 Power Management"
2189 depends on OLPC && MFD_CS5535 && PM_SLEEP
2190 select MFD_CORE
2191 ---help---
2192 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2193
2194 config OLPC_XO1_RTC
2195 bool "OLPC XO-1 Real Time Clock"
2196 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2197 ---help---
2198 Add support for the XO-1 real time clock, which can be used as a
2199 programmable wakeup source.
2200
2201 config OLPC_XO1_SCI
2202 bool "OLPC XO-1 SCI extras"
2203 depends on OLPC && OLPC_XO1_PM
2204 depends on INPUT=y
2205 select POWER_SUPPLY
2206 select GPIO_CS5535
2207 select MFD_CORE
2208 ---help---
2209 Add support for SCI-based features of the OLPC XO-1 laptop:
2210 - EC-driven system wakeups
2211 - Power button
2212 - Ebook switch
2213 - Lid switch
2214 - AC adapter status updates
2215 - Battery status updates
2216
2217 config OLPC_XO15_SCI
2218 bool "OLPC XO-1.5 SCI extras"
2219 depends on OLPC && ACPI
2220 select POWER_SUPPLY
2221 ---help---
2222 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2223 - EC-driven system wakeups
2224 - AC adapter status updates
2225 - Battery status updates
2226
2227 config ALIX
2228 bool "PCEngines ALIX System Support (LED setup)"
2229 select GPIOLIB
2230 ---help---
2231 This option enables system support for the PCEngines ALIX.
2232 At present this just sets up LEDs for GPIO control on
2233 ALIX2/3/6 boards. However, other system specific setup should
2234 get added here.
2235
2236 Note: You must still enable the drivers for GPIO and LED support
2237 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2238
2239 Note: You have to set alix.force=1 for boards with Award BIOS.
2240
2241 config NET5501
2242 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2243 select GPIOLIB
2244 ---help---
2245 This option enables system support for the Soekris Engineering net5501.
2246
2247 config GEOS
2248 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2249 select GPIOLIB
2250 depends on DMI
2251 ---help---
2252 This option enables system support for the Traverse Technologies GEOS.
2253
2254 config TS5500
2255 bool "Technologic Systems TS-5500 platform support"
2256 depends on MELAN
2257 select CHECK_SIGNATURE
2258 select NEW_LEDS
2259 select LEDS_CLASS
2260 ---help---
2261 This option enables system support for the Technologic Systems TS-5500.
2262
2263 endif # X86_32
2264
2265 config AMD_NB
2266 def_bool y
2267 depends on CPU_SUP_AMD && PCI
2268
2269 source "drivers/pcmcia/Kconfig"
2270
2271 source "drivers/pci/hotplug/Kconfig"
2272
2273 config RAPIDIO
2274 tristate "RapidIO support"
2275 depends on PCI
2276 default n
2277 help
2278 If enabled this option will include drivers and the core
2279 infrastructure code to support RapidIO interconnect devices.
2280
2281 source "drivers/rapidio/Kconfig"
2282
2283 config X86_SYSFB
2284 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2285 help
2286 Firmwares often provide initial graphics framebuffers so the BIOS,
2287 bootloader or kernel can show basic video-output during boot for
2288 user-guidance and debugging. Historically, x86 used the VESA BIOS
2289 Extensions and EFI-framebuffers for this, which are mostly limited
2290 to x86.
2291 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2292 framebuffers so the new generic system-framebuffer drivers can be
2293 used on x86. If the framebuffer is not compatible with the generic
2294 modes, it is adverticed as fallback platform framebuffer so legacy
2295 drivers like efifb, vesafb and uvesafb can pick it up.
2296 If this option is not selected, all system framebuffers are always
2297 marked as fallback platform framebuffers as usual.
2298
2299 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2300 not be able to pick up generic system framebuffers if this option
2301 is selected. You are highly encouraged to enable simplefb as
2302 replacement if you select this option. simplefb can correctly deal
2303 with generic system framebuffers. But you should still keep vesafb
2304 and others enabled as fallback if a system framebuffer is
2305 incompatible with simplefb.
2306
2307 If unsure, say Y.
2308
2309 endmenu
2310
2311
2312 menu "Executable file formats / Emulations"
2313
2314 source "fs/Kconfig.binfmt"
2315
2316 config IA32_EMULATION
2317 bool "IA32 Emulation"
2318 depends on X86_64
2319 select BINFMT_ELF
2320 select COMPAT_BINFMT_ELF
2321 select HAVE_UID16
2322 ---help---
2323 Include code to run legacy 32-bit programs under a
2324 64-bit kernel. You should likely turn this on, unless you're
2325 100% sure that you don't have any 32-bit programs left.
2326
2327 config IA32_AOUT
2328 tristate "IA32 a.out support"
2329 depends on IA32_EMULATION
2330 ---help---
2331 Support old a.out binaries in the 32bit emulation.
2332
2333 config X86_X32
2334 bool "x32 ABI for 64-bit mode"
2335 depends on X86_64 && IA32_EMULATION
2336 ---help---
2337 Include code to run binaries for the x32 native 32-bit ABI
2338 for 64-bit processors. An x32 process gets access to the
2339 full 64-bit register file and wide data path while leaving
2340 pointers at 32 bits for smaller memory footprint.
2341
2342 You will need a recent binutils (2.22 or later) with
2343 elf32_x86_64 support enabled to compile a kernel with this
2344 option set.
2345
2346 config COMPAT
2347 def_bool y
2348 depends on IA32_EMULATION || X86_X32
2349 select ARCH_WANT_OLD_COMPAT_IPC
2350
2351 if COMPAT
2352 config COMPAT_FOR_U64_ALIGNMENT
2353 def_bool y
2354
2355 config SYSVIPC_COMPAT
2356 def_bool y
2357 depends on SYSVIPC
2358
2359 config KEYS_COMPAT
2360 def_bool y
2361 depends on KEYS
2362 endif
2363
2364 endmenu
2365
2366
2367 config HAVE_ATOMIC_IOMAP
2368 def_bool y
2369 depends on X86_32
2370
2371 config X86_DEV_DMA_OPS
2372 bool
2373 depends on X86_64 || STA2X11
2374
2375 config X86_DMA_REMAP
2376 bool
2377 depends on STA2X11
2378
2379 config IOSF_MBI
2380 tristate
2381 default m
2382 depends on 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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