| blob | 2f645c90e4d8c6858c9347fd16617eddb0431ac2 |
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
9 config X86_32
10 def_bool y
11 depends on !64BIT
12 select CLKSRC_I8253
13 select HAVE_UID16
15 config X86_64
16 def_bool y
17 depends on 64BIT
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
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 HAVE_OPTPROBES
47 select HAVE_KPROBES_ON_FTRACE
48 select HAVE_FTRACE_MCOUNT_RECORD
49 select HAVE_FENTRY if X86_64
50 select HAVE_C_RECORDMCOUNT
51 select HAVE_DYNAMIC_FTRACE
52 select HAVE_DYNAMIC_FTRACE_WITH_REGS
53 select HAVE_FUNCTION_TRACER
54 select HAVE_FUNCTION_GRAPH_TRACER
55 select HAVE_FUNCTION_GRAPH_FP_TEST
56 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
57 select HAVE_SYSCALL_TRACEPOINTS
58 select SYSCTL_EXCEPTION_TRACE
59 select HAVE_KVM
60 select HAVE_ARCH_KGDB
61 select HAVE_ARCH_TRACEHOOK
62 select HAVE_GENERIC_DMA_COHERENT if X86_32
63 select HAVE_EFFICIENT_UNALIGNED_ACCESS
64 select USER_STACKTRACE_SUPPORT
65 select HAVE_REGS_AND_STACK_ACCESS_API
66 select HAVE_DMA_API_DEBUG
67 select HAVE_KERNEL_GZIP
68 select HAVE_KERNEL_BZIP2
69 select HAVE_KERNEL_LZMA
70 select HAVE_KERNEL_XZ
71 select HAVE_KERNEL_LZO
72 select HAVE_KERNEL_LZ4
73 select HAVE_HW_BREAKPOINT
74 select HAVE_MIXED_BREAKPOINTS_REGS
75 select PERF_EVENTS
76 select HAVE_PERF_EVENTS_NMI
77 select HAVE_PERF_REGS
78 select HAVE_PERF_USER_STACK_DUMP
79 select HAVE_DEBUG_KMEMLEAK
80 select ANON_INODES
81 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
82 select HAVE_CMPXCHG_LOCAL
83 select HAVE_CMPXCHG_DOUBLE
84 select HAVE_ARCH_KMEMCHECK
85 select HAVE_USER_RETURN_NOTIFIER
86 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
87 select HAVE_ARCH_JUMP_LABEL
88 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
89 select SPARSE_IRQ
90 select GENERIC_FIND_FIRST_BIT
91 select GENERIC_IRQ_PROBE
92 select GENERIC_PENDING_IRQ if SMP
93 select GENERIC_IRQ_SHOW
94 select GENERIC_CLOCKEVENTS_MIN_ADJUST
95 select IRQ_FORCED_THREADING
96 select HAVE_BPF_JIT if X86_64
97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
98 select CLKEVT_I8253
99 select ARCH_HAVE_NMI_SAFE_CMPXCHG
100 select GENERIC_IOMAP
101 select DCACHE_WORD_ACCESS
102 select GENERIC_SMP_IDLE_THREAD
103 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
104 select HAVE_ARCH_SECCOMP_FILTER
105 select BUILDTIME_EXTABLE_SORT
106 select GENERIC_CMOS_UPDATE
107 select HAVE_ARCH_SOFT_DIRTY
108 select CLOCKSOURCE_WATCHDOG
109 select GENERIC_CLOCKEVENTS
110 select ARCH_CLOCKSOURCE_DATA if X86_64
111 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
112 select GENERIC_TIME_VSYSCALL if X86_64
113 select KTIME_SCALAR if X86_32
114 select GENERIC_STRNCPY_FROM_USER
115 select GENERIC_STRNLEN_USER
116 select HAVE_CONTEXT_TRACKING if X86_64
117 select HAVE_IRQ_TIME_ACCOUNTING
118 select VIRT_TO_BUS
119 select MODULES_USE_ELF_REL if X86_32
120 select MODULES_USE_ELF_RELA if X86_64
121 select CLONE_BACKWARDS if X86_32
122 select ARCH_USE_BUILTIN_BSWAP
123 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
124 select OLD_SIGACTION if X86_32
125 select COMPAT_OLD_SIGACTION if IA32_EMULATION
126 select RTC_LIB
127 select HAVE_DEBUG_STACKOVERFLOW
128 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
129 select HAVE_CC_STACKPROTECTOR
130 select ARCH_SUPPORTS_ATOMIC_RMW
132 config INSTRUCTION_DECODER
133 def_bool y
134 depends on KPROBES || PERF_EVENTS || UPROBES
136 config OUTPUT_FORMAT
137 string
138 default "elf32-i386" if X86_32
139 default "elf64-x86-64" if X86_64
141 config ARCH_DEFCONFIG
142 string
143 default "arch/x86/configs/i386_defconfig" if X86_32
144 default "arch/x86/configs/x86_64_defconfig" if X86_64
146 config LOCKDEP_SUPPORT
147 def_bool y
149 config STACKTRACE_SUPPORT
150 def_bool y
152 config HAVE_LATENCYTOP_SUPPORT
153 def_bool y
155 config MMU
156 def_bool y
158 config SBUS
159 bool
161 config NEED_DMA_MAP_STATE
162 def_bool y
163 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
165 config NEED_SG_DMA_LENGTH
166 def_bool y
168 config GENERIC_ISA_DMA
169 def_bool y
170 depends on ISA_DMA_API
172 config GENERIC_BUG
173 def_bool y
174 depends on BUG
175 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
177 config GENERIC_BUG_RELATIVE_POINTERS
178 bool
180 config GENERIC_HWEIGHT
181 def_bool y
183 config ARCH_MAY_HAVE_PC_FDC
184 def_bool y
185 depends on ISA_DMA_API
187 config RWSEM_XCHGADD_ALGORITHM
188 def_bool y
190 config GENERIC_CALIBRATE_DELAY
191 def_bool y
193 config ARCH_HAS_CPU_RELAX
194 def_bool y
196 config ARCH_HAS_CACHE_LINE_SIZE
197 def_bool y
199 config ARCH_HAS_CPU_AUTOPROBE
200 def_bool y
202 config HAVE_SETUP_PER_CPU_AREA
203 def_bool y
205 config NEED_PER_CPU_EMBED_FIRST_CHUNK
206 def_bool y
208 config NEED_PER_CPU_PAGE_FIRST_CHUNK
209 def_bool y
211 config ARCH_HIBERNATION_POSSIBLE
212 def_bool y
214 config ARCH_SUSPEND_POSSIBLE
215 def_bool y
217 config ARCH_WANT_HUGE_PMD_SHARE
218 def_bool y
220 config ARCH_WANT_GENERAL_HUGETLB
221 def_bool y
223 config ZONE_DMA32
224 bool
225 default X86_64
227 config AUDIT_ARCH
228 bool
229 default X86_64
231 config ARCH_SUPPORTS_OPTIMIZED_INLINING
232 def_bool y
234 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
235 def_bool y
237 config HAVE_INTEL_TXT
238 def_bool y
239 depends on INTEL_IOMMU && ACPI
241 config X86_32_SMP
242 def_bool y
243 depends on X86_32 && SMP
245 config X86_64_SMP
246 def_bool y
247 depends on X86_64 && SMP
249 config X86_HT
250 def_bool y
251 depends on SMP
253 config X86_32_LAZY_GS
254 def_bool y
255 depends on X86_32 && !CC_STACKPROTECTOR
257 config ARCH_HWEIGHT_CFLAGS
258 string
259 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
260 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
262 config ARCH_SUPPORTS_UPROBES
263 def_bool y
265 source "init/Kconfig"
266 source "kernel/Kconfig.freezer"
268 menu "Processor type and features"
270 config ZONE_DMA
271 bool "DMA memory allocation support" if EXPERT
272 default y
273 help
274 DMA memory allocation support allows devices with less than 32-bit
275 addressing to allocate within the first 16MB of address space.
276 Disable if no such devices will be used.
278 If unsure, say Y.
280 config SMP
281 bool "Symmetric multi-processing support"
282 ---help---
283 This enables support for systems with more than one CPU. If you have
284 a system with only one CPU, say N. If you have a system with more
285 than one CPU, say Y.
287 If you say N here, the kernel will run on uni- and multiprocessor
288 machines, but will use only one CPU of a multiprocessor machine. If
289 you say Y here, the kernel will run on many, but not all,
290 uniprocessor machines. On a uniprocessor machine, the kernel
291 will run faster if you say N here.
293 Note that if you say Y here and choose architecture "586" or
294 "Pentium" under "Processor family", the kernel will not work on 486
295 architectures. Similarly, multiprocessor kernels for the "PPro"
296 architecture may not work on all Pentium based boards.
298 People using multiprocessor machines who say Y here should also say
299 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
300 Management" code will be disabled if you say Y here.
302 See also <file:Documentation/x86/i386/IO-APIC.txt>,
303 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
304 <http://www.tldp.org/docs.html#howto>.
306 If you don't know what to do here, say N.
308 config X86_X2APIC
309 bool "Support x2apic"
310 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
311 ---help---
312 This enables x2apic support on CPUs that have this feature.
314 This allows 32-bit apic IDs (so it can support very large systems),
315 and accesses the local apic via MSRs not via mmio.
317 If you don't know what to do here, say N.
319 config X86_MPPARSE
320 bool "Enable MPS table" if ACPI || SFI
321 default y
322 depends on X86_LOCAL_APIC
323 ---help---
324 For old smp systems that do not have proper acpi support. Newer systems
325 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
327 config X86_BIGSMP
328 bool "Support for big SMP systems with more than 8 CPUs"
329 depends on X86_32 && SMP
330 ---help---
331 This option is needed for the systems that have more than 8 CPUs
333 config GOLDFISH
334 def_bool y
335 depends on X86_GOLDFISH
337 if X86_32
338 config X86_EXTENDED_PLATFORM
339 bool "Support for extended (non-PC) x86 platforms"
340 default y
341 ---help---
342 If you disable this option then the kernel will only support
343 standard PC platforms. (which covers the vast majority of
344 systems out there.)
346 If you enable this option then you'll be able to select support
347 for the following (non-PC) 32 bit x86 platforms:
348 Goldfish (Android emulator)
349 AMD Elan
350 NUMAQ (IBM/Sequent)
351 RDC R-321x SoC
352 SGI 320/540 (Visual Workstation)
353 STA2X11-based (e.g. Northville)
354 Summit/EXA (IBM x440)
355 Unisys ES7000 IA32 series
356 Moorestown MID devices
358 If you have one of these systems, or if you want to build a
359 generic distribution kernel, say Y here - otherwise say N.
360 endif
362 if X86_64
363 config X86_EXTENDED_PLATFORM
364 bool "Support for extended (non-PC) x86 platforms"
365 default y
366 ---help---
367 If you disable this option then the kernel will only support
368 standard PC platforms. (which covers the vast majority of
369 systems out there.)
371 If you enable this option then you'll be able to select support
372 for the following (non-PC) 64 bit x86 platforms:
373 Numascale NumaChip
374 ScaleMP vSMP
375 SGI Ultraviolet
377 If you have one of these systems, or if you want to build a
378 generic distribution kernel, say Y here - otherwise say N.
379 endif
380 # This is an alphabetically sorted list of 64 bit extended platforms
381 # Please maintain the alphabetic order if and when there are additions
382 config X86_NUMACHIP
383 bool "Numascale NumaChip"
384 depends on X86_64
385 depends on X86_EXTENDED_PLATFORM
386 depends on NUMA
387 depends on SMP
388 depends on X86_X2APIC
389 depends on PCI_MMCONFIG
390 ---help---
391 Adds support for Numascale NumaChip large-SMP systems. Needed to
392 enable more than ~168 cores.
393 If you don't have one of these, you should say N here.
395 config X86_VSMP
396 bool "ScaleMP vSMP"
397 select HYPERVISOR_GUEST
398 select PARAVIRT
399 depends on X86_64 && PCI
400 depends on X86_EXTENDED_PLATFORM
401 depends on SMP
402 ---help---
403 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
404 supposed to run on these EM64T-based machines. Only choose this option
405 if you have one of these machines.
407 config X86_UV
408 bool "SGI Ultraviolet"
409 depends on X86_64
410 depends on X86_EXTENDED_PLATFORM
411 depends on NUMA
412 depends on X86_X2APIC
413 ---help---
414 This option is needed in order to support SGI Ultraviolet systems.
415 If you don't have one of these, you should say N here.
417 # Following is an alphabetically sorted list of 32 bit extended platforms
418 # Please maintain the alphabetic order if and when there are additions
420 config X86_GOLDFISH
421 bool "Goldfish (Virtual Platform)"
422 depends on X86_32
423 depends on X86_EXTENDED_PLATFORM
424 ---help---
425 Enable support for the Goldfish virtual platform used primarily
426 for Android development. Unless you are building for the Android
427 Goldfish emulator say N here.
429 config X86_INTEL_CE
430 bool "CE4100 TV platform"
431 depends on PCI
432 depends on PCI_GODIRECT
433 depends on X86_32
434 depends on X86_EXTENDED_PLATFORM
435 select X86_REBOOTFIXUPS
436 select OF
437 select OF_EARLY_FLATTREE
438 select IRQ_DOMAIN
439 ---help---
440 Select for the Intel CE media processor (CE4100) SOC.
441 This option compiles in support for the CE4100 SOC for settop
442 boxes and media devices.
444 config X86_INTEL_MID
445 bool "Intel MID platform support"
446 depends on X86_32
447 depends on X86_EXTENDED_PLATFORM
448 depends on X86_PLATFORM_DEVICES
449 depends on PCI
450 depends on PCI_GOANY
451 depends on X86_IO_APIC
452 select SFI
453 select I2C
454 select DW_APB_TIMER
455 select APB_TIMER
456 select INTEL_SCU_IPC
457 select MFD_INTEL_MSIC
458 ---help---
459 Select to build a kernel capable of supporting Intel MID (Mobile
460 Internet Device) platform systems which do not have the PCI legacy
461 interfaces. If you are building for a PC class system say N here.
463 Intel MID platforms are based on an Intel processor and chipset which
464 consume less power than most of the x86 derivatives.
466 config X86_INTEL_LPSS
467 bool "Intel Low Power Subsystem Support"
468 depends on ACPI
469 select COMMON_CLK
470 select PINCTRL
471 ---help---
472 Select to build support for Intel Low Power Subsystem such as
473 found on Intel Lynxpoint PCH. Selecting this option enables
474 things like clock tree (common clock framework) and pincontrol
475 which are needed by the LPSS peripheral drivers.
477 config X86_RDC321X
478 bool "RDC R-321x SoC"
479 depends on X86_32
480 depends on X86_EXTENDED_PLATFORM
481 select M486
482 select X86_REBOOTFIXUPS
483 ---help---
484 This option is needed for RDC R-321x system-on-chip, also known
485 as R-8610-(G).
486 If you don't have one of these chips, you should say N here.
488 config X86_32_NON_STANDARD
489 bool "Support non-standard 32-bit SMP architectures"
490 depends on X86_32 && SMP
491 depends on X86_EXTENDED_PLATFORM
492 ---help---
493 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
494 STA2X11, default subarchitectures. It is intended for a generic
495 binary kernel. If you select them all, kernel will probe it
496 one by one and will fallback to default.
498 # Alphabetically sorted list of Non standard 32 bit platforms
500 config X86_NUMAQ
501 bool "NUMAQ (IBM/Sequent)"
502 depends on X86_32_NON_STANDARD
503 depends on PCI
504 select NUMA
505 select X86_MPPARSE
506 ---help---
507 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
508 NUMA multiquad box. This changes the way that processors are
509 bootstrapped, and uses Clustered Logical APIC addressing mode instead
510 of Flat Logical. You will need a new lynxer.elf file to flash your
511 firmware with - send email to <Martin.Bligh@us.ibm.com>.
513 config X86_SUPPORTS_MEMORY_FAILURE
514 def_bool y
515 # MCE code calls memory_failure():
516 depends on X86_MCE
517 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
518 depends on !X86_NUMAQ
519 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
520 depends on X86_64 || !SPARSEMEM
521 select ARCH_SUPPORTS_MEMORY_FAILURE
523 config X86_VISWS
524 bool "SGI 320/540 (Visual Workstation)"
525 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
526 depends on X86_32_NON_STANDARD
527 ---help---
528 The SGI Visual Workstation series is an IA32-based workstation
529 based on SGI systems chips with some legacy PC hardware attached.
531 Say Y here to create a kernel to run on the SGI 320 or 540.
533 A kernel compiled for the Visual Workstation will run on general
534 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
536 config STA2X11
537 bool "STA2X11 Companion Chip Support"
538 depends on X86_32_NON_STANDARD && PCI
539 select X86_DEV_DMA_OPS
540 select X86_DMA_REMAP
541 select SWIOTLB
542 select MFD_STA2X11
543 select ARCH_REQUIRE_GPIOLIB
544 default n
545 ---help---
546 This adds support for boards based on the STA2X11 IO-Hub,
547 a.k.a. "ConneXt". The chip is used in place of the standard
548 PC chipset, so all "standard" peripherals are missing. If this
549 option is selected the kernel will still be able to boot on
550 standard PC machines.
552 config X86_SUMMIT
553 bool "Summit/EXA (IBM x440)"
554 depends on X86_32_NON_STANDARD
555 ---help---
556 This option is needed for IBM systems that use the Summit/EXA chipset.
557 In particular, it is needed for the x440.
559 config X86_ES7000
560 bool "Unisys ES7000 IA32 series"
561 depends on X86_32_NON_STANDARD && X86_BIGSMP
562 ---help---
563 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
564 supposed to run on an IA32-based Unisys ES7000 system.
566 config X86_32_IRIS
567 tristate "Eurobraille/Iris poweroff module"
568 depends on X86_32
569 ---help---
570 The Iris machines from EuroBraille do not have APM or ACPI support
571 to shut themselves down properly. A special I/O sequence is
572 needed to do so, which is what this module does at
573 kernel shutdown.
575 This is only for Iris machines from EuroBraille.
577 If unused, say N.
579 config SCHED_OMIT_FRAME_POINTER
580 def_bool y
581 prompt "Single-depth WCHAN output"
582 depends on X86
583 ---help---
584 Calculate simpler /proc/<PID>/wchan values. If this option
585 is disabled then wchan values will recurse back to the
586 caller function. This provides more accurate wchan values,
587 at the expense of slightly more scheduling overhead.
589 If in doubt, say "Y".
591 menuconfig HYPERVISOR_GUEST
592 bool "Linux guest support"
593 ---help---
594 Say Y here to enable options for running Linux under various hyper-
595 visors. This option enables basic hypervisor detection and platform
596 setup.
598 If you say N, all options in this submenu will be skipped and
599 disabled, and Linux guest support won't be built in.
601 if HYPERVISOR_GUEST
603 config PARAVIRT
604 bool "Enable paravirtualization code"
605 ---help---
606 This changes the kernel so it can modify itself when it is run
607 under a hypervisor, potentially improving performance significantly
608 over full virtualization. However, when run without a hypervisor
609 the kernel is theoretically slower and slightly larger.
611 config PARAVIRT_DEBUG
612 bool "paravirt-ops debugging"
613 depends on PARAVIRT && DEBUG_KERNEL
614 ---help---
615 Enable to debug paravirt_ops internals. Specifically, BUG if
616 a paravirt_op is missing when it is called.
618 config PARAVIRT_SPINLOCKS
619 bool "Paravirtualization layer for spinlocks"
620 depends on PARAVIRT && SMP
621 select UNINLINE_SPIN_UNLOCK
622 ---help---
623 Paravirtualized spinlocks allow a pvops backend to replace the
624 spinlock implementation with something virtualization-friendly
625 (for example, block the virtual CPU rather than spinning).
627 It has a minimal impact on native kernels and gives a nice performance
628 benefit on paravirtualized KVM / Xen kernels.
630 If you are unsure how to answer this question, answer Y.
632 source "arch/x86/xen/Kconfig"
634 config KVM_GUEST
635 bool "KVM Guest support (including kvmclock)"
636 depends on PARAVIRT
637 select PARAVIRT_CLOCK
638 default y
639 ---help---
640 This option enables various optimizations for running under the KVM
641 hypervisor. It includes a paravirtualized clock, so that instead
642 of relying on a PIT (or probably other) emulation by the
643 underlying device model, the host provides the guest with
644 timing infrastructure such as time of day, and system time
646 config KVM_DEBUG_FS
647 bool "Enable debug information for KVM Guests in debugfs"
648 depends on KVM_GUEST && DEBUG_FS
649 default n
650 ---help---
651 This option enables collection of various statistics for KVM guest.
652 Statistics are displayed in debugfs filesystem. Enabling this option
653 may incur significant overhead.
655 source "arch/x86/lguest/Kconfig"
657 config PARAVIRT_TIME_ACCOUNTING
658 bool "Paravirtual steal time accounting"
659 depends on PARAVIRT
660 default n
661 ---help---
662 Select this option to enable fine granularity task steal time
663 accounting. Time spent executing other tasks in parallel with
664 the current vCPU is discounted from the vCPU power. To account for
665 that, there can be a small performance impact.
667 If in doubt, say N here.
669 config PARAVIRT_CLOCK
670 bool
672 endif #HYPERVISOR_GUEST
674 config NO_BOOTMEM
675 def_bool y
677 config MEMTEST
678 bool "Memtest"
679 ---help---
680 This option adds a kernel parameter 'memtest', which allows memtest
681 to be set.
682 memtest=0, mean disabled; -- default
683 memtest=1, mean do 1 test pattern;
684 ...
685 memtest=4, mean do 4 test patterns.
686 If you are unsure how to answer this question, answer N.
688 config X86_SUMMIT_NUMA
689 def_bool y
690 depends on X86_32 && NUMA && X86_32_NON_STANDARD
692 config X86_CYCLONE_TIMER
693 def_bool y
694 depends on X86_SUMMIT
696 source "arch/x86/Kconfig.cpu"
698 config HPET_TIMER
699 def_bool X86_64
700 prompt "HPET Timer Support" if X86_32
701 ---help---
702 Use the IA-PC HPET (High Precision Event Timer) to manage
703 time in preference to the PIT and RTC, if a HPET is
704 present.
705 HPET is the next generation timer replacing legacy 8254s.
706 The HPET provides a stable time base on SMP
707 systems, unlike the TSC, but it is more expensive to access,
708 as it is off-chip. You can find the HPET spec at
709 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
711 You can safely choose Y here. However, HPET will only be
712 activated if the platform and the BIOS support this feature.
713 Otherwise the 8254 will be used for timing services.
715 Choose N to continue using the legacy 8254 timer.
717 config HPET_EMULATE_RTC
718 def_bool y
719 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
721 config APB_TIMER
722 def_bool y if X86_INTEL_MID
723 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
724 select DW_APB_TIMER
725 depends on X86_INTEL_MID && SFI
726 help
727 APB timer is the replacement for 8254, HPET on X86 MID platforms.
728 The APBT provides a stable time base on SMP
729 systems, unlike the TSC, but it is more expensive to access,
730 as it is off-chip. APB timers are always running regardless of CPU
731 C states, they are used as per CPU clockevent device when possible.
733 # Mark as expert because too many people got it wrong.
734 # The code disables itself when not needed.
735 config DMI
736 default y
737 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
738 bool "Enable DMI scanning" if EXPERT
739 ---help---
740 Enabled scanning of DMI to identify machine quirks. Say Y
741 here unless you have verified that your setup is not
742 affected by entries in the DMI blacklist. Required by PNP
743 BIOS code.
745 config GART_IOMMU
746 bool "Old AMD GART IOMMU support"
747 select SWIOTLB
748 depends on X86_64 && PCI && AMD_NB
749 ---help---
750 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
751 GART based hardware IOMMUs.
753 The GART supports full DMA access for devices with 32-bit access
754 limitations, on systems with more than 3 GB. This is usually needed
755 for USB, sound, many IDE/SATA chipsets and some other devices.
757 Newer systems typically have a modern AMD IOMMU, supported via
758 the CONFIG_AMD_IOMMU=y config option.
760 In normal configurations this driver is only active when needed:
761 there's more than 3 GB of memory and the system contains a
762 32-bit limited device.
764 If unsure, say Y.
766 config CALGARY_IOMMU
767 bool "IBM Calgary IOMMU support"
768 select SWIOTLB
769 depends on X86_64 && PCI
770 ---help---
771 Support for hardware IOMMUs in IBM's xSeries x366 and x460
772 systems. Needed to run systems with more than 3GB of memory
773 properly with 32-bit PCI devices that do not support DAC
774 (Double Address Cycle). Calgary also supports bus level
775 isolation, where all DMAs pass through the IOMMU. This
776 prevents them from going anywhere except their intended
777 destination. This catches hard-to-find kernel bugs and
778 mis-behaving drivers and devices that do not use the DMA-API
779 properly to set up their DMA buffers. The IOMMU can be
780 turned off at boot time with the iommu=off parameter.
781 Normally the kernel will make the right choice by itself.
782 If unsure, say Y.
784 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
785 def_bool y
786 prompt "Should Calgary be enabled by default?"
787 depends on CALGARY_IOMMU
788 ---help---
789 Should Calgary be enabled by default? if you choose 'y', Calgary
790 will be used (if it exists). If you choose 'n', Calgary will not be
791 used even if it exists. If you choose 'n' and would like to use
792 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
793 If unsure, say Y.
795 # need this always selected by IOMMU for the VIA workaround
796 config SWIOTLB
797 def_bool y if X86_64
798 ---help---
799 Support for software bounce buffers used on x86-64 systems
800 which don't have a hardware IOMMU. Using this PCI devices
801 which can only access 32-bits of memory can be used on systems
802 with more than 3 GB of memory.
803 If unsure, say Y.
805 config IOMMU_HELPER
806 def_bool y
807 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
809 config MAXSMP
810 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
811 depends on X86_64 && SMP && DEBUG_KERNEL
812 select CPUMASK_OFFSTACK
813 ---help---
814 Enable maximum number of CPUS and NUMA Nodes for this architecture.
815 If unsure, say N.
817 config NR_CPUS
818 int "Maximum number of CPUs" if SMP && !MAXSMP
819 range 2 8 if SMP && X86_32 && !X86_BIGSMP
820 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
821 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
822 default "1" if !SMP
823 default "8192" if MAXSMP
824 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
825 default "8" if SMP
826 ---help---
827 This allows you to specify the maximum number of CPUs which this
828 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
829 supported value is 4096, otherwise the maximum value is 512. The
830 minimum value which makes sense is 2.
832 This is purely to save memory - each supported CPU adds
833 approximately eight kilobytes to the kernel image.
835 config SCHED_SMT
836 bool "SMT (Hyperthreading) scheduler support"
837 depends on X86_HT
838 ---help---
839 SMT scheduler support improves the CPU scheduler's decision making
840 when dealing with Intel Pentium 4 chips with HyperThreading at a
841 cost of slightly increased overhead in some places. If unsure say
842 N here.
844 config SCHED_MC
845 def_bool y
846 prompt "Multi-core scheduler support"
847 depends on X86_HT
848 ---help---
849 Multi-core scheduler support improves the CPU scheduler's decision
850 making when dealing with multi-core CPU chips at a cost of slightly
851 increased overhead in some places. If unsure say N here.
853 source "kernel/Kconfig.preempt"
855 config X86_UP_APIC
856 bool "Local APIC support on uniprocessors"
857 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
858 ---help---
859 A local APIC (Advanced Programmable Interrupt Controller) is an
860 integrated interrupt controller in the CPU. If you have a single-CPU
861 system which has a processor with a local APIC, you can say Y here to
862 enable and use it. If you say Y here even though your machine doesn't
863 have a local APIC, then the kernel will still run with no slowdown at
864 all. The local APIC supports CPU-generated self-interrupts (timer,
865 performance counters), and the NMI watchdog which detects hard
866 lockups.
868 config X86_UP_APIC_MSI
869 def_bool y
870 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
872 config X86_UP_IOAPIC
873 bool "IO-APIC support on uniprocessors"
874 depends on X86_UP_APIC
875 ---help---
876 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
877 SMP-capable replacement for PC-style interrupt controllers. Most
878 SMP systems and many recent uniprocessor systems have one.
880 If you have a single-CPU system with an IO-APIC, you can say Y here
881 to use it. If you say Y here even though your machine doesn't have
882 an IO-APIC, then the kernel will still run with no slowdown at all.
884 config X86_LOCAL_APIC
885 def_bool y
886 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
888 config X86_IO_APIC
889 def_bool y
890 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
892 config X86_VISWS_APIC
893 def_bool y
894 depends on X86_32 && X86_VISWS
896 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
897 bool "Reroute for broken boot IRQs"
898 depends on X86_IO_APIC
899 ---help---
900 This option enables a workaround that fixes a source of
901 spurious interrupts. This is recommended when threaded
902 interrupt handling is used on systems where the generation of
903 superfluous "boot interrupts" cannot be disabled.
905 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
906 entry in the chipset's IO-APIC is masked (as, e.g. the RT
907 kernel does during interrupt handling). On chipsets where this
908 boot IRQ generation cannot be disabled, this workaround keeps
909 the original IRQ line masked so that only the equivalent "boot
910 IRQ" is delivered to the CPUs. The workaround also tells the
911 kernel to set up the IRQ handler on the boot IRQ line. In this
912 way only one interrupt is delivered to the kernel. Otherwise
913 the spurious second interrupt may cause the kernel to bring
914 down (vital) interrupt lines.
916 Only affects "broken" chipsets. Interrupt sharing may be
917 increased on these systems.
919 config X86_MCE
920 bool "Machine Check / overheating reporting"
921 default y
922 ---help---
923 Machine Check support allows the processor to notify the
924 kernel if it detects a problem (e.g. overheating, data corruption).
925 The action the kernel takes depends on the severity of the problem,
926 ranging from warning messages to halting the machine.
928 config X86_MCE_INTEL
929 def_bool y
930 prompt "Intel MCE features"
931 depends on X86_MCE && X86_LOCAL_APIC
932 ---help---
933 Additional support for intel specific MCE features such as
934 the thermal monitor.
936 config X86_MCE_AMD
937 def_bool y
938 prompt "AMD MCE features"
939 depends on X86_MCE && X86_LOCAL_APIC
940 ---help---
941 Additional support for AMD specific MCE features such as
942 the DRAM Error Threshold.
944 config X86_ANCIENT_MCE
945 bool "Support for old Pentium 5 / WinChip machine checks"
946 depends on X86_32 && X86_MCE
947 ---help---
948 Include support for machine check handling on old Pentium 5 or WinChip
949 systems. These typically need to be enabled explicitly on the command
950 line.
952 config X86_MCE_THRESHOLD
953 depends on X86_MCE_AMD || X86_MCE_INTEL
954 def_bool y
956 config X86_MCE_INJECT
957 depends on X86_MCE
958 tristate "Machine check injector support"
959 ---help---
960 Provide support for injecting machine checks for testing purposes.
961 If you don't know what a machine check is and you don't do kernel
962 QA it is safe to say n.
964 config X86_THERMAL_VECTOR
965 def_bool y
966 depends on X86_MCE_INTEL
968 config VM86
969 bool "Enable VM86 support" if EXPERT
970 default y
971 depends on X86_32
972 ---help---
973 This option is required by programs like DOSEMU to run
974 16-bit real mode legacy code on x86 processors. It also may
975 be needed by software like XFree86 to initialize some video
976 cards via BIOS. Disabling this option saves about 6K.
978 config X86_16BIT
979 bool "Enable support for 16-bit segments" if EXPERT
980 default y
981 ---help---
982 This option is required by programs like Wine to run 16-bit
983 protected mode legacy code on x86 processors. Disabling
984 this option saves about 300 bytes on i386, or around 6K text
985 plus 16K runtime memory on x86-64,
987 config X86_ESPFIX32
988 def_bool y
989 depends on X86_16BIT && X86_32
991 config X86_ESPFIX64
992 def_bool y
993 depends on X86_16BIT && X86_64
995 config TOSHIBA
996 tristate "Toshiba Laptop support"
997 depends on X86_32
998 ---help---
999 This adds a driver to safely access the System Management Mode of
1000 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1001 not work on models with a Phoenix BIOS. The System Management Mode
1002 is used to set the BIOS and power saving options on Toshiba portables.
1004 For information on utilities to make use of this driver see the
1005 Toshiba Linux utilities web site at:
1006 <http://www.buzzard.org.uk/toshiba/>.
1008 Say Y if you intend to run this kernel on a Toshiba portable.
1009 Say N otherwise.
1011 config I8K
1012 tristate "Dell laptop support"
1013 select HWMON
1014 ---help---
1015 This adds a driver to safely access the System Management Mode
1016 of the CPU on the Dell Inspiron 8000. The System Management Mode
1017 is used to read cpu temperature and cooling fan status and to
1018 control the fans on the I8K portables.
1020 This driver has been tested only on the Inspiron 8000 but it may
1021 also work with other Dell laptops. You can force loading on other
1022 models by passing the parameter `force=1' to the module. Use at
1023 your own risk.
1025 For information on utilities to make use of this driver see the
1026 I8K Linux utilities web site at:
1027 <http://people.debian.org/~dz/i8k/>
1029 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1030 Say N otherwise.
1032 config X86_REBOOTFIXUPS
1033 bool "Enable X86 board specific fixups for reboot"
1034 depends on X86_32
1035 ---help---
1036 This enables chipset and/or board specific fixups to be done
1037 in order to get reboot to work correctly. This is only needed on
1038 some combinations of hardware and BIOS. The symptom, for which
1039 this config is intended, is when reboot ends with a stalled/hung
1040 system.
1042 Currently, the only fixup is for the Geode machines using
1043 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1045 Say Y if you want to enable the fixup. Currently, it's safe to
1046 enable this option even if you don't need it.
1047 Say N otherwise.
1049 config MICROCODE
1050 tristate "CPU microcode loading support"
1051 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1052 select FW_LOADER
1053 ---help---
1055 If you say Y here, you will be able to update the microcode on
1056 certain Intel and AMD processors. The Intel support is for the
1057 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1058 Xeon etc. The AMD support is for families 0x10 and later. You will
1059 obviously need the actual microcode binary data itself which is not
1060 shipped with the Linux kernel.
1062 This option selects the general module only, you need to select
1063 at least one vendor specific module as well.
1065 To compile this driver as a module, choose M here: the module
1066 will be called microcode.
1068 config MICROCODE_INTEL
1069 bool "Intel microcode loading support"
1070 depends on MICROCODE
1071 default MICROCODE
1072 select FW_LOADER
1073 ---help---
1074 This options enables microcode patch loading support for Intel
1075 processors.
1077 For the current Intel microcode data package go to
1078 <https://downloadcenter.intel.com> and search for
1079 'Linux Processor Microcode Data File'.
1081 config MICROCODE_AMD
1082 bool "AMD microcode loading support"
1083 depends on MICROCODE
1084 select FW_LOADER
1085 ---help---
1086 If you select this option, microcode patch loading support for AMD
1087 processors will be enabled.
1089 config MICROCODE_OLD_INTERFACE
1090 def_bool y
1091 depends on MICROCODE
1093 config MICROCODE_INTEL_EARLY
1094 def_bool n
1096 config MICROCODE_AMD_EARLY
1097 def_bool n
1099 config MICROCODE_EARLY
1100 bool "Early load microcode"
1101 depends on MICROCODE=y && BLK_DEV_INITRD
1102 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1103 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1104 default y
1105 help
1106 This option provides functionality to read additional microcode data
1107 at the beginning of initrd image. The data tells kernel to load
1108 microcode to CPU's as early as possible. No functional change if no
1109 microcode data is glued to the initrd, therefore it's safe to say Y.
1111 config X86_MSR
1112 tristate "/dev/cpu/*/msr - Model-specific register support"
1113 ---help---
1114 This device gives privileged processes access to the x86
1115 Model-Specific Registers (MSRs). It is a character device with
1116 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1117 MSR accesses are directed to a specific CPU on multi-processor
1118 systems.
1120 config X86_CPUID
1121 tristate "/dev/cpu/*/cpuid - CPU information support"
1122 ---help---
1123 This device gives processes access to the x86 CPUID instruction to
1124 be executed on a specific processor. It is a character device
1125 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1126 /dev/cpu/31/cpuid.
1128 choice
1129 prompt "High Memory Support"
1130 default HIGHMEM64G if X86_NUMAQ
1131 default HIGHMEM4G
1132 depends on X86_32
1134 config NOHIGHMEM
1135 bool "off"
1136 depends on !X86_NUMAQ
1137 ---help---
1138 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1139 However, the address space of 32-bit x86 processors is only 4
1140 Gigabytes large. That means that, if you have a large amount of
1141 physical memory, not all of it can be "permanently mapped" by the
1142 kernel. The physical memory that's not permanently mapped is called
1143 "high memory".
1145 If you are compiling a kernel which will never run on a machine with
1146 more than 1 Gigabyte total physical RAM, answer "off" here (default
1147 choice and suitable for most users). This will result in a "3GB/1GB"
1148 split: 3GB are mapped so that each process sees a 3GB virtual memory
1149 space and the remaining part of the 4GB virtual memory space is used
1150 by the kernel to permanently map as much physical memory as
1151 possible.
1153 If the machine has between 1 and 4 Gigabytes physical RAM, then
1154 answer "4GB" here.
1156 If more than 4 Gigabytes is used then answer "64GB" here. This
1157 selection turns Intel PAE (Physical Address Extension) mode on.
1158 PAE implements 3-level paging on IA32 processors. PAE is fully
1159 supported by Linux, PAE mode is implemented on all recent Intel
1160 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1161 then the kernel will not boot on CPUs that don't support PAE!
1163 The actual amount of total physical memory will either be
1164 auto detected or can be forced by using a kernel command line option
1165 such as "mem=256M". (Try "man bootparam" or see the documentation of
1166 your boot loader (lilo or loadlin) about how to pass options to the
1167 kernel at boot time.)
1169 If unsure, say "off".
1171 config HIGHMEM4G
1172 bool "4GB"
1173 depends on !X86_NUMAQ
1174 ---help---
1175 Select this if you have a 32-bit processor and between 1 and 4
1176 gigabytes of physical RAM.
1178 config HIGHMEM64G
1179 bool "64GB"
1180 depends on !M486
1181 select X86_PAE
1182 ---help---
1183 Select this if you have a 32-bit processor and more than 4
1184 gigabytes of physical RAM.
1186 endchoice
1188 choice
1189 prompt "Memory split" if EXPERT
1190 default VMSPLIT_3G
1191 depends on X86_32
1192 ---help---
1193 Select the desired split between kernel and user memory.
1195 If the address range available to the kernel is less than the
1196 physical memory installed, the remaining memory will be available
1197 as "high memory". Accessing high memory is a little more costly
1198 than low memory, as it needs to be mapped into the kernel first.
1199 Note that increasing the kernel address space limits the range
1200 available to user programs, making the address space there
1201 tighter. Selecting anything other than the default 3G/1G split
1202 will also likely make your kernel incompatible with binary-only
1203 kernel modules.
1205 If you are not absolutely sure what you are doing, leave this
1206 option alone!
1208 config VMSPLIT_3G
1209 bool "3G/1G user/kernel split"
1210 config VMSPLIT_3G_OPT
1211 depends on !X86_PAE
1212 bool "3G/1G user/kernel split (for full 1G low memory)"
1213 config VMSPLIT_2G
1214 bool "2G/2G user/kernel split"
1215 config VMSPLIT_2G_OPT
1216 depends on !X86_PAE
1217 bool "2G/2G user/kernel split (for full 2G low memory)"
1218 config VMSPLIT_1G
1219 bool "1G/3G user/kernel split"
1220 endchoice
1222 config PAGE_OFFSET
1223 hex
1224 default 0xB0000000 if VMSPLIT_3G_OPT
1225 default 0x80000000 if VMSPLIT_2G
1226 default 0x78000000 if VMSPLIT_2G_OPT
1227 default 0x40000000 if VMSPLIT_1G
1228 default 0xC0000000
1229 depends on X86_32
1231 config HIGHMEM
1232 def_bool y
1233 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1235 config X86_PAE
1236 bool "PAE (Physical Address Extension) Support"
1237 depends on X86_32 && !HIGHMEM4G
1238 ---help---
1239 PAE is required for NX support, and furthermore enables
1240 larger swapspace support for non-overcommit purposes. It
1241 has the cost of more pagetable lookup overhead, and also
1242 consumes more pagetable space per process.
1244 config ARCH_PHYS_ADDR_T_64BIT
1245 def_bool y
1246 depends on X86_64 || X86_PAE
1248 config ARCH_DMA_ADDR_T_64BIT
1249 def_bool y
1250 depends on X86_64 || HIGHMEM64G
1252 config DIRECT_GBPAGES
1253 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1254 default y
1255 depends on X86_64
1256 ---help---
1257 Allow the kernel linear mapping to use 1GB pages on CPUs that
1258 support it. This can improve the kernel's performance a tiny bit by
1259 reducing TLB pressure. If in doubt, say "Y".
1261 # Common NUMA Features
1262 config NUMA
1263 bool "Numa Memory Allocation and Scheduler Support"
1264 depends on SMP
1265 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1266 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1267 ---help---
1268 Enable NUMA (Non Uniform Memory Access) support.
1270 The kernel will try to allocate memory used by a CPU on the
1271 local memory controller of the CPU and add some more
1272 NUMA awareness to the kernel.
1274 For 64-bit this is recommended if the system is Intel Core i7
1275 (or later), AMD Opteron, or EM64T NUMA.
1277 For 32-bit this is only needed on (rare) 32-bit-only platforms
1278 that support NUMA topologies, such as NUMAQ / Summit, or if you
1279 boot a 32-bit kernel on a 64-bit NUMA platform.
1281 Otherwise, you should say N.
1283 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1284 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1286 config AMD_NUMA
1287 def_bool y
1288 prompt "Old style AMD Opteron NUMA detection"
1289 depends on X86_64 && NUMA && PCI
1290 ---help---
1291 Enable AMD NUMA node topology detection. You should say Y here if
1292 you have a multi processor AMD system. This uses an old method to
1293 read the NUMA configuration directly from the builtin Northbridge
1294 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1295 which also takes priority if both are compiled in.
1297 config X86_64_ACPI_NUMA
1298 def_bool y
1299 prompt "ACPI NUMA detection"
1300 depends on X86_64 && NUMA && ACPI && PCI
1301 select ACPI_NUMA
1302 ---help---
1303 Enable ACPI SRAT based node topology detection.
1305 # Some NUMA nodes have memory ranges that span
1306 # other nodes. Even though a pfn is valid and
1307 # between a node's start and end pfns, it may not
1308 # reside on that node. See memmap_init_zone()
1309 # for details.
1310 config NODES_SPAN_OTHER_NODES
1311 def_bool y
1312 depends on X86_64_ACPI_NUMA
1314 config NUMA_EMU
1315 bool "NUMA emulation"
1316 depends on NUMA
1317 ---help---
1318 Enable NUMA emulation. A flat machine will be split
1319 into virtual nodes when booted with "numa=fake=N", where N is the
1320 number of nodes. This is only useful for debugging.
1322 config NODES_SHIFT
1323 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1324 range 1 10
1325 default "10" if MAXSMP
1326 default "6" if X86_64
1327 default "4" if X86_NUMAQ
1328 default "3"
1329 depends on NEED_MULTIPLE_NODES
1330 ---help---
1331 Specify the maximum number of NUMA Nodes available on the target
1332 system. Increases memory reserved to accommodate various tables.
1334 config ARCH_HAVE_MEMORY_PRESENT
1335 def_bool y
1336 depends on X86_32 && DISCONTIGMEM
1338 config NEED_NODE_MEMMAP_SIZE
1339 def_bool y
1340 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1342 config ARCH_FLATMEM_ENABLE
1343 def_bool y
1344 depends on X86_32 && !NUMA
1346 config ARCH_DISCONTIGMEM_ENABLE
1347 def_bool y
1348 depends on NUMA && X86_32
1350 config ARCH_DISCONTIGMEM_DEFAULT
1351 def_bool y
1352 depends on NUMA && X86_32
1354 config ARCH_SPARSEMEM_ENABLE
1355 def_bool y
1356 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1357 select SPARSEMEM_STATIC if X86_32
1358 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1360 config ARCH_SPARSEMEM_DEFAULT
1361 def_bool y
1362 depends on X86_64
1364 config ARCH_SELECT_MEMORY_MODEL
1365 def_bool y
1366 depends on ARCH_SPARSEMEM_ENABLE
1368 config ARCH_MEMORY_PROBE
1369 bool "Enable sysfs memory/probe interface"
1370 depends on X86_64 && MEMORY_HOTPLUG
1371 help
1372 This option enables a sysfs memory/probe interface for testing.
1373 See Documentation/memory-hotplug.txt for more information.
1374 If you are unsure how to answer this question, answer N.
1376 config ARCH_PROC_KCORE_TEXT
1377 def_bool y
1378 depends on X86_64 && PROC_KCORE
1380 config ILLEGAL_POINTER_VALUE
1381 hex
1382 default 0 if X86_32
1383 default 0xdead000000000000 if X86_64
1385 source "mm/Kconfig"
1387 config HIGHPTE
1388 bool "Allocate 3rd-level pagetables from highmem"
1389 depends on HIGHMEM
1390 ---help---
1391 The VM uses one page table entry for each page of physical memory.
1392 For systems with a lot of RAM, this can be wasteful of precious
1393 low memory. Setting this option will put user-space page table
1394 entries in high memory.
1396 config X86_CHECK_BIOS_CORRUPTION
1397 bool "Check for low memory corruption"
1398 ---help---
1399 Periodically check for memory corruption in low memory, which
1400 is suspected to be caused by BIOS. Even when enabled in the
1401 configuration, it is disabled at runtime. Enable it by
1402 setting "memory_corruption_check=1" on the kernel command
1403 line. By default it scans the low 64k of memory every 60
1404 seconds; see the memory_corruption_check_size and
1405 memory_corruption_check_period parameters in
1406 Documentation/kernel-parameters.txt to adjust this.
1408 When enabled with the default parameters, this option has
1409 almost no overhead, as it reserves a relatively small amount
1410 of memory and scans it infrequently. It both detects corruption
1411 and prevents it from affecting the running system.
1413 It is, however, intended as a diagnostic tool; if repeatable
1414 BIOS-originated corruption always affects the same memory,
1415 you can use memmap= to prevent the kernel from using that
1416 memory.
1418 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1419 bool "Set the default setting of memory_corruption_check"
1420 depends on X86_CHECK_BIOS_CORRUPTION
1421 default y
1422 ---help---
1423 Set whether the default state of memory_corruption_check is
1424 on or off.
1426 config X86_RESERVE_LOW
1427 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1428 default 64
1429 range 4 640
1430 ---help---
1431 Specify the amount of low memory to reserve for the BIOS.
1433 The first page contains BIOS data structures that the kernel
1434 must not use, so that page must always be reserved.
1436 By default we reserve the first 64K of physical RAM, as a
1437 number of BIOSes are known to corrupt that memory range
1438 during events such as suspend/resume or monitor cable
1439 insertion, so it must not be used by the kernel.
1441 You can set this to 4 if you are absolutely sure that you
1442 trust the BIOS to get all its memory reservations and usages
1443 right. If you know your BIOS have problems beyond the
1444 default 64K area, you can set this to 640 to avoid using the
1445 entire low memory range.
1447 If you have doubts about the BIOS (e.g. suspend/resume does
1448 not work or there's kernel crashes after certain hardware
1449 hotplug events) then you might want to enable
1450 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1451 typical corruption patterns.
1453 Leave this to the default value of 64 if you are unsure.
1455 config MATH_EMULATION
1456 bool
1457 prompt "Math emulation" if X86_32
1458 ---help---
1459 Linux can emulate a math coprocessor (used for floating point
1460 operations) if you don't have one. 486DX and Pentium processors have
1461 a math coprocessor built in, 486SX and 386 do not, unless you added
1462 a 487DX or 387, respectively. (The messages during boot time can
1463 give you some hints here ["man dmesg"].) Everyone needs either a
1464 coprocessor or this emulation.
1466 If you don't have a math coprocessor, you need to say Y here; if you
1467 say Y here even though you have a coprocessor, the coprocessor will
1468 be used nevertheless. (This behavior can be changed with the kernel
1469 command line option "no387", which comes handy if your coprocessor
1470 is broken. Try "man bootparam" or see the documentation of your boot
1471 loader (lilo or loadlin) about how to pass options to the kernel at
1472 boot time.) This means that it is a good idea to say Y here if you
1473 intend to use this kernel on different machines.
1475 More information about the internals of the Linux math coprocessor
1476 emulation can be found in <file:arch/x86/math-emu/README>.
1478 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1479 kernel, it won't hurt.
1481 config MTRR
1482 def_bool y
1483 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1484 ---help---
1485 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1486 the Memory Type Range Registers (MTRRs) may be used to control
1487 processor access to memory ranges. This is most useful if you have
1488 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1489 allows bus write transfers to be combined into a larger transfer
1490 before bursting over the PCI/AGP bus. This can increase performance
1491 of image write operations 2.5 times or more. Saying Y here creates a
1492 /proc/mtrr file which may be used to manipulate your processor's
1493 MTRRs. Typically the X server should use this.
1495 This code has a reasonably generic interface so that similar
1496 control registers on other processors can be easily supported
1497 as well:
1499 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1500 Registers (ARRs) which provide a similar functionality to MTRRs. For
1501 these, the ARRs are used to emulate the MTRRs.
1502 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1503 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1504 write-combining. All of these processors are supported by this code
1505 and it makes sense to say Y here if you have one of them.
1507 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1508 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1509 can lead to all sorts of problems, so it's good to say Y here.
1511 You can safely say Y even if your machine doesn't have MTRRs, you'll
1512 just add about 9 KB to your kernel.
1514 See <file:Documentation/x86/mtrr.txt> for more information.
1516 config MTRR_SANITIZER
1517 def_bool y
1518 prompt "MTRR cleanup support"
1519 depends on MTRR
1520 ---help---
1521 Convert MTRR layout from continuous to discrete, so X drivers can
1522 add writeback entries.
1524 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1525 The largest mtrr entry size for a continuous block can be set with
1526 mtrr_chunk_size.
1528 If unsure, say Y.
1530 config MTRR_SANITIZER_ENABLE_DEFAULT
1531 int "MTRR cleanup enable value (0-1)"
1532 range 0 1
1533 default "0"
1534 depends on MTRR_SANITIZER
1535 ---help---
1536 Enable mtrr cleanup default value
1538 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1539 int "MTRR cleanup spare reg num (0-7)"
1540 range 0 7
1541 default "1"
1542 depends on MTRR_SANITIZER
1543 ---help---
1544 mtrr cleanup spare entries default, it can be changed via
1545 mtrr_spare_reg_nr=N on the kernel command line.
1547 config X86_PAT
1548 def_bool y
1549 prompt "x86 PAT support" if EXPERT
1550 depends on MTRR
1551 ---help---
1552 Use PAT attributes to setup page level cache control.
1554 PATs are the modern equivalents of MTRRs and are much more
1555 flexible than MTRRs.
1557 Say N here if you see bootup problems (boot crash, boot hang,
1558 spontaneous reboots) or a non-working video driver.
1560 If unsure, say Y.
1562 config ARCH_USES_PG_UNCACHED
1563 def_bool y
1564 depends on X86_PAT
1566 config ARCH_RANDOM
1567 def_bool y
1568 prompt "x86 architectural random number generator" if EXPERT
1569 ---help---
1570 Enable the x86 architectural RDRAND instruction
1571 (Intel Bull Mountain technology) to generate random numbers.
1572 If supported, this is a high bandwidth, cryptographically
1573 secure hardware random number generator.
1575 config X86_SMAP
1576 def_bool y
1577 prompt "Supervisor Mode Access Prevention" if EXPERT
1578 ---help---
1579 Supervisor Mode Access Prevention (SMAP) is a security
1580 feature in newer Intel processors. There is a small
1581 performance cost if this enabled and turned on; there is
1582 also a small increase in the kernel size if this is enabled.
1584 If unsure, say Y.
1586 config EFI
1587 bool "EFI runtime service support"
1588 depends on ACPI
1589 select UCS2_STRING
1590 ---help---
1591 This enables the kernel to use EFI runtime services that are
1592 available (such as the EFI variable services).
1594 This option is only useful on systems that have EFI firmware.
1595 In addition, you should use the latest ELILO loader available
1596 at <http://elilo.sourceforge.net> in order to take advantage
1597 of EFI runtime services. However, even with this option, the
1598 resultant kernel should continue to boot on existing non-EFI
1599 platforms.
1601 config EFI_STUB
1602 bool "EFI stub support"
1603 depends on EFI
1604 select RELOCATABLE
1605 ---help---
1606 This kernel feature allows a bzImage to be loaded directly
1607 by EFI firmware without the use of a bootloader.
1609 See Documentation/efi-stub.txt for more information.
1611 config SECCOMP
1612 def_bool y
1613 prompt "Enable seccomp to safely compute untrusted bytecode"
1614 ---help---
1615 This kernel feature is useful for number crunching applications
1616 that may need to compute untrusted bytecode during their
1617 execution. By using pipes or other transports made available to
1618 the process as file descriptors supporting the read/write
1619 syscalls, it's possible to isolate those applications in
1620 their own address space using seccomp. Once seccomp is
1621 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1622 and the task is only allowed to execute a few safe syscalls
1623 defined by each seccomp mode.
1625 If unsure, say Y. Only embedded should say N here.
1627 source kernel/Kconfig.hz
1629 config KEXEC
1630 bool "kexec system call"
1631 ---help---
1632 kexec is a system call that implements the ability to shutdown your
1633 current kernel, and to start another kernel. It is like a reboot
1634 but it is independent of the system firmware. And like a reboot
1635 you can start any kernel with it, not just Linux.
1637 The name comes from the similarity to the exec system call.
1639 It is an ongoing process to be certain the hardware in a machine
1640 is properly shutdown, so do not be surprised if this code does not
1641 initially work for you. As of this writing the exact hardware
1642 interface is strongly in flux, so no good recommendation can be
1643 made.
1645 config CRASH_DUMP
1646 bool "kernel crash dumps"
1647 depends on X86_64 || (X86_32 && HIGHMEM)
1648 ---help---
1649 Generate crash dump after being started by kexec.
1650 This should be normally only set in special crash dump kernels
1651 which are loaded in the main kernel with kexec-tools into
1652 a specially reserved region and then later executed after
1653 a crash by kdump/kexec. The crash dump kernel must be compiled
1654 to a memory address not used by the main kernel or BIOS using
1655 PHYSICAL_START, or it must be built as a relocatable image
1656 (CONFIG_RELOCATABLE=y).
1657 For more details see Documentation/kdump/kdump.txt
1659 config KEXEC_JUMP
1660 bool "kexec jump"
1661 depends on KEXEC && HIBERNATION
1662 ---help---
1663 Jump between original kernel and kexeced kernel and invoke
1664 code in physical address mode via KEXEC
1666 config PHYSICAL_START
1667 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1668 default "0x1000000"
1669 ---help---
1670 This gives the physical address where the kernel is loaded.
1672 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1673 bzImage will decompress itself to above physical address and
1674 run from there. Otherwise, bzImage will run from the address where
1675 it has been loaded by the boot loader and will ignore above physical
1676 address.
1678 In normal kdump cases one does not have to set/change this option
1679 as now bzImage can be compiled as a completely relocatable image
1680 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1681 address. This option is mainly useful for the folks who don't want
1682 to use a bzImage for capturing the crash dump and want to use a
1683 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1684 to be specifically compiled to run from a specific memory area
1685 (normally a reserved region) and this option comes handy.
1687 So if you are using bzImage for capturing the crash dump,
1688 leave the value here unchanged to 0x1000000 and set
1689 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1690 for capturing the crash dump change this value to start of
1691 the reserved region. In other words, it can be set based on
1692 the "X" value as specified in the "crashkernel=YM@XM"
1693 command line boot parameter passed to the panic-ed
1694 kernel. Please take a look at Documentation/kdump/kdump.txt
1695 for more details about crash dumps.
1697 Usage of bzImage for capturing the crash dump is recommended as
1698 one does not have to build two kernels. Same kernel can be used
1699 as production kernel and capture kernel. Above option should have
1700 gone away after relocatable bzImage support is introduced. But it
1701 is present because there are users out there who continue to use
1702 vmlinux for dump capture. This option should go away down the
1703 line.
1705 Don't change this unless you know what you are doing.
1707 config RELOCATABLE
1708 bool "Build a relocatable kernel"
1709 default y
1710 ---help---
1711 This builds a kernel image that retains relocation information
1712 so it can be loaded someplace besides the default 1MB.
1713 The relocations tend to make the kernel binary about 10% larger,
1714 but are discarded at runtime.
1716 One use is for the kexec on panic case where the recovery kernel
1717 must live at a different physical address than the primary
1718 kernel.
1720 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1721 it has been loaded at and the compile time physical address
1722 (CONFIG_PHYSICAL_START) is used as the minimum location.
1724 config RANDOMIZE_BASE
1725 bool "Randomize the address of the kernel image"
1726 depends on RELOCATABLE
1727 depends on !HIBERNATION
1728 default n
1729 ---help---
1730 Randomizes the physical and virtual address at which the
1731 kernel image is decompressed, as a security feature that
1732 deters exploit attempts relying on knowledge of the location
1733 of kernel internals.
1735 Entropy is generated using the RDRAND instruction if it is
1736 supported. If RDTSC is supported, it is used as well. If
1737 neither RDRAND nor RDTSC are supported, then randomness is
1738 read from the i8254 timer.
1740 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1741 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1742 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1743 minimum of 2MiB, only 10 bits of entropy is theoretically
1744 possible. At best, due to page table layouts, 64-bit can use
1745 9 bits of entropy and 32-bit uses 8 bits.
1747 If unsure, say N.
1749 config RANDOMIZE_BASE_MAX_OFFSET
1750 hex "Maximum kASLR offset allowed" if EXPERT
1751 depends on RANDOMIZE_BASE
1752 range 0x0 0x20000000 if X86_32
1753 default "0x20000000" if X86_32
1754 range 0x0 0x40000000 if X86_64
1755 default "0x40000000" if X86_64
1756 ---help---
1757 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1758 memory is used to determine the maximal offset in bytes that will
1759 be applied to the kernel when kernel Address Space Layout
1760 Randomization (kASLR) is active. This must be a multiple of
1761 PHYSICAL_ALIGN.
1763 On 32-bit this is limited to 512MiB by page table layouts. The
1764 default is 512MiB.
1766 On 64-bit this is limited by how the kernel fixmap page table is
1767 positioned, so this cannot be larger than 1GiB currently. Without
1768 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1769 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1770 modules area will shrink to compensate, up to the current maximum
1771 1GiB to 1GiB split. The default is 1GiB.
1773 If unsure, leave at the default value.
1775 # Relocation on x86 needs some additional build support
1776 config X86_NEED_RELOCS
1777 def_bool y
1778 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1780 config PHYSICAL_ALIGN
1781 hex "Alignment value to which kernel should be aligned"
1782 default "0x200000"
1783 range 0x2000 0x1000000 if X86_32
1784 range 0x200000 0x1000000 if X86_64
1785 ---help---
1786 This value puts the alignment restrictions on physical address
1787 where kernel is loaded and run from. Kernel is compiled for an
1788 address which meets above alignment restriction.
1790 If bootloader loads the kernel at a non-aligned address and
1791 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1792 address aligned to above value and run from there.
1794 If bootloader loads the kernel at a non-aligned address and
1795 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1796 load address and decompress itself to the address it has been
1797 compiled for and run from there. The address for which kernel is
1798 compiled already meets above alignment restrictions. Hence the
1799 end result is that kernel runs from a physical address meeting
1800 above alignment restrictions.
1802 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1803 this value must be a multiple of 0x200000.
1805 Don't change this unless you know what you are doing.
1807 config HOTPLUG_CPU
1808 bool "Support for hot-pluggable CPUs"
1809 depends on SMP
1810 ---help---
1811 Say Y here to allow turning CPUs off and on. CPUs can be
1812 controlled through /sys/devices/system/cpu.
1813 ( Note: power management support will enable this option
1814 automatically on SMP systems. )
1815 Say N if you want to disable CPU hotplug.
1817 config BOOTPARAM_HOTPLUG_CPU0
1818 bool "Set default setting of cpu0_hotpluggable"
1819 default n
1820 depends on HOTPLUG_CPU
1821 ---help---
1822 Set whether default state of cpu0_hotpluggable is on or off.
1824 Say Y here to enable CPU0 hotplug by default. If this switch
1825 is turned on, there is no need to give cpu0_hotplug kernel
1826 parameter and the CPU0 hotplug feature is enabled by default.
1828 Please note: there are two known CPU0 dependencies if you want
1829 to enable the CPU0 hotplug feature either by this switch or by
1830 cpu0_hotplug kernel parameter.
1832 First, resume from hibernate or suspend always starts from CPU0.
1833 So hibernate and suspend are prevented if CPU0 is offline.
1835 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1836 offline if any interrupt can not migrate out of CPU0. There may
1837 be other CPU0 dependencies.
1839 Please make sure the dependencies are under your control before
1840 you enable this feature.
1842 Say N if you don't want to enable CPU0 hotplug feature by default.
1843 You still can enable the CPU0 hotplug feature at boot by kernel
1844 parameter cpu0_hotplug.
1846 config DEBUG_HOTPLUG_CPU0
1847 def_bool n
1848 prompt "Debug CPU0 hotplug"
1849 depends on HOTPLUG_CPU
1850 ---help---
1851 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1852 soon as possible and boots up userspace with CPU0 offlined. User
1853 can online CPU0 back after boot time.
1855 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1856 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1857 compilation or giving cpu0_hotplug kernel parameter at boot.
1859 If unsure, say N.
1861 config COMPAT_VDSO
1862 def_bool y
1863 prompt "Compat VDSO support"
1864 depends on X86_32 || IA32_EMULATION
1865 ---help---
1866 Map the 32-bit VDSO to the predictable old-style address too.
1868 Say N here if you are running a sufficiently recent glibc
1869 version (2.3.3 or later), to remove the high-mapped
1870 VDSO mapping and to exclusively use the randomized VDSO.
1872 If unsure, say Y.
1874 config CMDLINE_BOOL
1875 bool "Built-in kernel command line"
1876 ---help---
1877 Allow for specifying boot arguments to the kernel at
1878 build time. On some systems (e.g. embedded ones), it is
1879 necessary or convenient to provide some or all of the
1880 kernel boot arguments with the kernel itself (that is,
1881 to not rely on the boot loader to provide them.)
1883 To compile command line arguments into the kernel,
1884 set this option to 'Y', then fill in the
1885 the boot arguments in CONFIG_CMDLINE.
1887 Systems with fully functional boot loaders (i.e. non-embedded)
1888 should leave this option set to 'N'.
1890 config CMDLINE
1891 string "Built-in kernel command string"
1892 depends on CMDLINE_BOOL
1893 default ""
1894 ---help---
1895 Enter arguments here that should be compiled into the kernel
1896 image and used at boot time. If the boot loader provides a
1897 command line at boot time, it is appended to this string to
1898 form the full kernel command line, when the system boots.
1900 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1901 change this behavior.
1903 In most cases, the command line (whether built-in or provided
1904 by the boot loader) should specify the device for the root
1905 file system.
1907 config CMDLINE_OVERRIDE
1908 bool "Built-in command line overrides boot loader arguments"
1909 depends on CMDLINE_BOOL
1910 ---help---
1911 Set this option to 'Y' to have the kernel ignore the boot loader
1912 command line, and use ONLY the built-in command line.
1914 This is used to work around broken boot loaders. This should
1915 be set to 'N' under normal conditions.
1917 endmenu
1919 config ARCH_ENABLE_MEMORY_HOTPLUG
1920 def_bool y
1921 depends on X86_64 || (X86_32 && HIGHMEM)
1923 config ARCH_ENABLE_MEMORY_HOTREMOVE
1924 def_bool y
1925 depends on MEMORY_HOTPLUG
1927 config USE_PERCPU_NUMA_NODE_ID
1928 def_bool y
1929 depends on NUMA
1931 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1932 def_bool y
1933 depends on X86_64 || X86_PAE
1935 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1936 def_bool y
1937 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1939 menu "Power management and ACPI options"
1941 config ARCH_HIBERNATION_HEADER
1942 def_bool y
1943 depends on X86_64 && HIBERNATION
1945 source "kernel/power/Kconfig"
1947 source "drivers/acpi/Kconfig"
1949 source "drivers/sfi/Kconfig"
1951 config X86_APM_BOOT
1952 def_bool y
1953 depends on APM
1955 menuconfig APM
1956 tristate "APM (Advanced Power Management) BIOS support"
1957 depends on X86_32 && PM_SLEEP
1958 ---help---
1959 APM is a BIOS specification for saving power using several different
1960 techniques. This is mostly useful for battery powered laptops with
1961 APM compliant BIOSes. If you say Y here, the system time will be
1962 reset after a RESUME operation, the /proc/apm device will provide
1963 battery status information, and user-space programs will receive
1964 notification of APM "events" (e.g. battery status change).
1966 If you select "Y" here, you can disable actual use of the APM
1967 BIOS by passing the "apm=off" option to the kernel at boot time.
1969 Note that the APM support is almost completely disabled for
1970 machines with more than one CPU.
1972 In order to use APM, you will need supporting software. For location
1973 and more information, read <file:Documentation/power/apm-acpi.txt>
1974 and the Battery Powered Linux mini-HOWTO, available from
1975 <http://www.tldp.org/docs.html#howto>.
1977 This driver does not spin down disk drives (see the hdparm(8)
1978 manpage ("man 8 hdparm") for that), and it doesn't turn off
1979 VESA-compliant "green" monitors.
1981 This driver does not support the TI 4000M TravelMate and the ACER
1982 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1983 desktop machines also don't have compliant BIOSes, and this driver
1984 may cause those machines to panic during the boot phase.
1986 Generally, if you don't have a battery in your machine, there isn't
1987 much point in using this driver and you should say N. If you get
1988 random kernel OOPSes or reboots that don't seem to be related to
1989 anything, try disabling/enabling this option (or disabling/enabling
1990 APM in your BIOS).
1992 Some other things you should try when experiencing seemingly random,
1993 "weird" problems:
1995 1) make sure that you have enough swap space and that it is
1996 enabled.
1997 2) pass the "no-hlt" option to the kernel
1998 3) switch on floating point emulation in the kernel and pass
1999 the "no387" option to the kernel
2000 4) pass the "floppy=nodma" option to the kernel
2001 5) pass the "mem=4M" option to the kernel (thereby disabling
2002 all but the first 4 MB of RAM)
2003 6) make sure that the CPU is not over clocked.
2004 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2005 8) disable the cache from your BIOS settings
2006 9) install a fan for the video card or exchange video RAM
2007 10) install a better fan for the CPU
2008 11) exchange RAM chips
2009 12) exchange the motherboard.
2011 To compile this driver as a module, choose M here: the
2012 module will be called apm.
2014 if APM
2016 config APM_IGNORE_USER_SUSPEND
2017 bool "Ignore USER SUSPEND"
2018 ---help---
2019 This option will ignore USER SUSPEND requests. On machines with a
2020 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2021 series notebooks, it is necessary to say Y because of a BIOS bug.
2023 config APM_DO_ENABLE
2024 bool "Enable PM at boot time"
2025 ---help---
2026 Enable APM features at boot time. From page 36 of the APM BIOS
2027 specification: "When disabled, the APM BIOS does not automatically
2028 power manage devices, enter the Standby State, enter the Suspend
2029 State, or take power saving steps in response to CPU Idle calls."
2030 This driver will make CPU Idle calls when Linux is idle (unless this
2031 feature is turned off -- see "Do CPU IDLE calls", below). This
2032 should always save battery power, but more complicated APM features
2033 will be dependent on your BIOS implementation. You may need to turn
2034 this option off if your computer hangs at boot time when using APM
2035 support, or if it beeps continuously instead of suspending. Turn
2036 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2037 T400CDT. This is off by default since most machines do fine without
2038 this feature.
2040 config APM_CPU_IDLE
2041 depends on CPU_IDLE
2042 bool "Make CPU Idle calls when idle"
2043 ---help---
2044 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2045 On some machines, this can activate improved power savings, such as
2046 a slowed CPU clock rate, when the machine is idle. These idle calls
2047 are made after the idle loop has run for some length of time (e.g.,
2048 333 mS). On some machines, this will cause a hang at boot time or
2049 whenever the CPU becomes idle. (On machines with more than one CPU,
2050 this option does nothing.)
2052 config APM_DISPLAY_BLANK
2053 bool "Enable console blanking using APM"
2054 ---help---
2055 Enable console blanking using the APM. Some laptops can use this to
2056 turn off the LCD backlight when the screen blanker of the Linux
2057 virtual console blanks the screen. Note that this is only used by
2058 the virtual console screen blanker, and won't turn off the backlight
2059 when using the X Window system. This also doesn't have anything to
2060 do with your VESA-compliant power-saving monitor. Further, this
2061 option doesn't work for all laptops -- it might not turn off your
2062 backlight at all, or it might print a lot of errors to the console,
2063 especially if you are using gpm.
2065 config APM_ALLOW_INTS
2066 bool "Allow interrupts during APM BIOS calls"
2067 ---help---
2068 Normally we disable external interrupts while we are making calls to
2069 the APM BIOS as a measure to lessen the effects of a badly behaving
2070 BIOS implementation. The BIOS should reenable interrupts if it
2071 needs to. Unfortunately, some BIOSes do not -- especially those in
2072 many of the newer IBM Thinkpads. If you experience hangs when you
2073 suspend, try setting this to Y. Otherwise, say N.
2075 endif # APM
2077 source "drivers/cpufreq/Kconfig"
2079 source "drivers/cpuidle/Kconfig"
2081 source "drivers/idle/Kconfig"
2083 endmenu
2086 menu "Bus options (PCI etc.)"
2088 config PCI
2089 bool "PCI support"
2090 default y
2091 ---help---
2092 Find out whether you have a PCI motherboard. PCI is the name of a
2093 bus system, i.e. the way the CPU talks to the other stuff inside
2094 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2095 VESA. If you have PCI, say Y, otherwise N.
2097 choice
2098 prompt "PCI access mode"
2099 depends on X86_32 && PCI
2100 default PCI_GOANY
2101 ---help---
2102 On PCI systems, the BIOS can be used to detect the PCI devices and
2103 determine their configuration. However, some old PCI motherboards
2104 have BIOS bugs and may crash if this is done. Also, some embedded
2105 PCI-based systems don't have any BIOS at all. Linux can also try to
2106 detect the PCI hardware directly without using the BIOS.
2108 With this option, you can specify how Linux should detect the
2109 PCI devices. If you choose "BIOS", the BIOS will be used,
2110 if you choose "Direct", the BIOS won't be used, and if you
2111 choose "MMConfig", then PCI Express MMCONFIG will be used.
2112 If you choose "Any", the kernel will try MMCONFIG, then the
2113 direct access method and falls back to the BIOS if that doesn't
2114 work. If unsure, go with the default, which is "Any".
2116 config PCI_GOBIOS
2117 bool "BIOS"
2119 config PCI_GOMMCONFIG
2120 bool "MMConfig"
2122 config PCI_GODIRECT
2123 bool "Direct"
2125 config PCI_GOOLPC
2126 bool "OLPC XO-1"
2127 depends on OLPC
2129 config PCI_GOANY
2130 bool "Any"
2132 endchoice
2134 config PCI_BIOS
2135 def_bool y
2136 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2138 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2139 config PCI_DIRECT
2140 def_bool y
2141 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2143 config PCI_MMCONFIG
2144 def_bool y
2145 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2147 config PCI_OLPC
2148 def_bool y
2149 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2151 config PCI_XEN
2152 def_bool y
2153 depends on PCI && XEN
2154 select SWIOTLB_XEN
2156 config PCI_DOMAINS
2157 def_bool y
2158 depends on PCI
2160 config PCI_MMCONFIG
2161 bool "Support mmconfig PCI config space access"
2162 depends on X86_64 && PCI && ACPI
2164 config PCI_CNB20LE_QUIRK
2165 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2166 depends on PCI
2167 help
2168 Read the PCI windows out of the CNB20LE host bridge. This allows
2169 PCI hotplug to work on systems with the CNB20LE chipset which do
2170 not have ACPI.
2172 There's no public spec for this chipset, and this functionality
2173 is known to be incomplete.
2175 You should say N unless you know you need this.
2177 source "drivers/pci/pcie/Kconfig"
2179 source "drivers/pci/Kconfig"
2181 # x86_64 have no ISA slots, but can have ISA-style DMA.
2182 config ISA_DMA_API
2183 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2184 default y
2185 help
2186 Enables ISA-style DMA support for devices requiring such controllers.
2187 If unsure, say Y.
2189 if X86_32
2191 config ISA
2192 bool "ISA support"
2193 ---help---
2194 Find out whether you have ISA slots on your motherboard. ISA is the
2195 name of a bus system, i.e. the way the CPU talks to the other stuff
2196 inside your box. Other bus systems are PCI, EISA, MicroChannel
2197 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2198 newer boards don't support it. If you have ISA, say Y, otherwise N.
2200 config EISA
2201 bool "EISA support"
2202 depends on ISA
2203 ---help---
2204 The Extended Industry Standard Architecture (EISA) bus was
2205 developed as an open alternative to the IBM MicroChannel bus.
2207 The EISA bus provided some of the features of the IBM MicroChannel
2208 bus while maintaining backward compatibility with cards made for
2209 the older ISA bus. The EISA bus saw limited use between 1988 and
2210 1995 when it was made obsolete by the PCI bus.
2212 Say Y here if you are building a kernel for an EISA-based machine.
2214 Otherwise, say N.
2216 source "drivers/eisa/Kconfig"
2218 config SCx200
2219 tristate "NatSemi SCx200 support"
2220 ---help---
2221 This provides basic support for National Semiconductor's
2222 (now AMD's) Geode processors. The driver probes for the
2223 PCI-IDs of several on-chip devices, so its a good dependency
2224 for other scx200_* drivers.
2226 If compiled as a module, the driver is named scx200.
2228 config SCx200HR_TIMER
2229 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2230 depends on SCx200
2231 default y
2232 ---help---
2233 This driver provides a clocksource built upon the on-chip
2234 27MHz high-resolution timer. Its also a workaround for
2235 NSC Geode SC-1100's buggy TSC, which loses time when the
2236 processor goes idle (as is done by the scheduler). The
2237 other workaround is idle=poll boot option.
2239 config OLPC
2240 bool "One Laptop Per Child support"
2241 depends on !X86_PAE
2242 select GPIOLIB
2243 select OF
2244 select OF_PROMTREE
2245 select IRQ_DOMAIN
2246 ---help---
2247 Add support for detecting the unique features of the OLPC
2248 XO hardware.
2250 config OLPC_XO1_PM
2251 bool "OLPC XO-1 Power Management"
2252 depends on OLPC && MFD_CS5535 && PM_SLEEP
2253 select MFD_CORE
2254 ---help---
2255 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2257 config OLPC_XO1_RTC
2258 bool "OLPC XO-1 Real Time Clock"
2259 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2260 ---help---
2261 Add support for the XO-1 real time clock, which can be used as a
2262 programmable wakeup source.
2264 config OLPC_XO1_SCI
2265 bool "OLPC XO-1 SCI extras"
2266 depends on OLPC && OLPC_XO1_PM
2267 depends on INPUT=y
2268 select POWER_SUPPLY
2269 select GPIO_CS5535
2270 select MFD_CORE
2271 ---help---
2272 Add support for SCI-based features of the OLPC XO-1 laptop:
2273 - EC-driven system wakeups
2274 - Power button
2275 - Ebook switch
2276 - Lid switch
2277 - AC adapter status updates
2278 - Battery status updates
2280 config OLPC_XO15_SCI
2281 bool "OLPC XO-1.5 SCI extras"
2282 depends on OLPC && ACPI
2283 select POWER_SUPPLY
2284 ---help---
2285 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2286 - EC-driven system wakeups
2287 - AC adapter status updates
2288 - Battery status updates
2290 config ALIX
2291 bool "PCEngines ALIX System Support (LED setup)"
2292 select GPIOLIB
2293 ---help---
2294 This option enables system support for the PCEngines ALIX.
2295 At present this just sets up LEDs for GPIO control on
2296 ALIX2/3/6 boards. However, other system specific setup should
2297 get added here.
2299 Note: You must still enable the drivers for GPIO and LED support
2300 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2302 Note: You have to set alix.force=1 for boards with Award BIOS.
2304 config NET5501
2305 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2306 select GPIOLIB
2307 ---help---
2308 This option enables system support for the Soekris Engineering net5501.
2310 config GEOS
2311 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2312 select GPIOLIB
2313 depends on DMI
2314 ---help---
2315 This option enables system support for the Traverse Technologies GEOS.
2317 config TS5500
2318 bool "Technologic Systems TS-5500 platform support"
2319 depends on MELAN
2320 select CHECK_SIGNATURE
2321 select NEW_LEDS
2322 select LEDS_CLASS
2323 ---help---
2324 This option enables system support for the Technologic Systems TS-5500.
2326 endif # X86_32
2328 config AMD_NB
2329 def_bool y
2330 depends on CPU_SUP_AMD && PCI
2332 source "drivers/pcmcia/Kconfig"
2334 source "drivers/pci/hotplug/Kconfig"
2336 config RAPIDIO
2337 tristate "RapidIO support"
2338 depends on PCI
2339 default n
2340 help
2341 If enabled this option will include drivers and the core
2342 infrastructure code to support RapidIO interconnect devices.
2344 source "drivers/rapidio/Kconfig"
2346 config X86_SYSFB
2347 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2348 help
2349 Firmwares often provide initial graphics framebuffers so the BIOS,
2350 bootloader or kernel can show basic video-output during boot for
2351 user-guidance and debugging. Historically, x86 used the VESA BIOS
2352 Extensions and EFI-framebuffers for this, which are mostly limited
2353 to x86.
2354 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2355 framebuffers so the new generic system-framebuffer drivers can be
2356 used on x86. If the framebuffer is not compatible with the generic
2357 modes, it is adverticed as fallback platform framebuffer so legacy
2358 drivers like efifb, vesafb and uvesafb can pick it up.
2359 If this option is not selected, all system framebuffers are always
2360 marked as fallback platform framebuffers as usual.
2362 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2363 not be able to pick up generic system framebuffers if this option
2364 is selected. You are highly encouraged to enable simplefb as
2365 replacement if you select this option. simplefb can correctly deal
2366 with generic system framebuffers. But you should still keep vesafb
2367 and others enabled as fallback if a system framebuffer is
2368 incompatible with simplefb.
2370 If unsure, say Y.
2372 endmenu
2375 menu "Executable file formats / Emulations"
2377 source "fs/Kconfig.binfmt"
2379 config IA32_EMULATION
2380 bool "IA32 Emulation"
2381 depends on X86_64
2382 select BINFMT_ELF
2383 select COMPAT_BINFMT_ELF
2384 select HAVE_UID16
2385 ---help---
2386 Include code to run legacy 32-bit programs under a
2387 64-bit kernel. You should likely turn this on, unless you're
2388 100% sure that you don't have any 32-bit programs left.
2390 config IA32_AOUT
2391 tristate "IA32 a.out support"
2392 depends on IA32_EMULATION
2393 ---help---
2394 Support old a.out binaries in the 32bit emulation.
2396 config X86_X32
2397 bool "x32 ABI for 64-bit mode"
2398 depends on X86_64 && IA32_EMULATION
2399 ---help---
2400 Include code to run binaries for the x32 native 32-bit ABI
2401 for 64-bit processors. An x32 process gets access to the
2402 full 64-bit register file and wide data path while leaving
2403 pointers at 32 bits for smaller memory footprint.
2405 You will need a recent binutils (2.22 or later) with
2406 elf32_x86_64 support enabled to compile a kernel with this
2407 option set.
2409 config COMPAT
2410 def_bool y
2411 depends on IA32_EMULATION || X86_X32
2412 select ARCH_WANT_OLD_COMPAT_IPC
2414 if COMPAT
2415 config COMPAT_FOR_U64_ALIGNMENT
2416 def_bool y
2418 config SYSVIPC_COMPAT
2419 def_bool y
2420 depends on SYSVIPC
2422 config KEYS_COMPAT
2423 def_bool y
2424 depends on KEYS
2425 endif
2427 endmenu
2430 config HAVE_ATOMIC_IOMAP
2431 def_bool y
2432 depends on X86_32
2434 config X86_DEV_DMA_OPS
2435 bool
2436 depends on X86_64 || STA2X11
2438 config X86_DMA_REMAP
2439 bool
2440 depends on STA2X11
2442 config IOSF_MBI
2443 tristate
2444 default m
2445 depends on PCI
2447 source "net/Kconfig"
2449 source "drivers/Kconfig"
2451 source "drivers/firmware/Kconfig"
2453 source "fs/Kconfig"
2455 source "arch/x86/Kconfig.debug"
2457 source "security/Kconfig"
2459 source "crypto/Kconfig"
2461 source "arch/x86/kvm/Kconfig"
2463 source "lib/Kconfig"