| blob | f968d85271909513e27854561e7a40eb8dcb77aa |
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 HAVE_AOUT if X86_32
26 select HAVE_UNSTABLE_SCHED_CLOCK
27 select ARCH_SUPPORTS_NUMA_BALANCING
28 select ARCH_WANTS_PROT_NUMA_PROT_NONE
29 select HAVE_IDE
30 select HAVE_OPROFILE
31 select HAVE_PCSPKR_PLATFORM
32 select HAVE_PERF_EVENTS
33 select HAVE_IOREMAP_PROT
34 select HAVE_KPROBES
35 select HAVE_MEMBLOCK
36 select HAVE_MEMBLOCK_NODE_MAP
37 select ARCH_DISCARD_MEMBLOCK
38 select ARCH_WANT_OPTIONAL_GPIOLIB
39 select ARCH_WANT_FRAME_POINTERS
40 select HAVE_DMA_ATTRS
41 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
42 select HAVE_KRETPROBES
43 select HAVE_OPTPROBES
44 select HAVE_KPROBES_ON_FTRACE
45 select HAVE_FTRACE_MCOUNT_RECORD
46 select HAVE_FENTRY if X86_64
47 select HAVE_C_RECORDMCOUNT
48 select HAVE_DYNAMIC_FTRACE
49 select HAVE_DYNAMIC_FTRACE_WITH_REGS
50 select HAVE_FUNCTION_TRACER
51 select HAVE_FUNCTION_GRAPH_TRACER
52 select HAVE_FUNCTION_GRAPH_FP_TEST
53 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
54 select HAVE_SYSCALL_TRACEPOINTS
55 select SYSCTL_EXCEPTION_TRACE
56 select HAVE_KVM
57 select HAVE_ARCH_KGDB
58 select HAVE_ARCH_TRACEHOOK
59 select HAVE_GENERIC_DMA_COHERENT if X86_32
60 select HAVE_EFFICIENT_UNALIGNED_ACCESS
61 select USER_STACKTRACE_SUPPORT
62 select HAVE_REGS_AND_STACK_ACCESS_API
63 select HAVE_DMA_API_DEBUG
64 select HAVE_KERNEL_GZIP
65 select HAVE_KERNEL_BZIP2
66 select HAVE_KERNEL_LZMA
67 select HAVE_KERNEL_XZ
68 select HAVE_KERNEL_LZO
69 select HAVE_KERNEL_LZ4
70 select HAVE_HW_BREAKPOINT
71 select HAVE_MIXED_BREAKPOINTS_REGS
72 select PERF_EVENTS
73 select HAVE_PERF_EVENTS_NMI
74 select HAVE_PERF_REGS
75 select HAVE_PERF_USER_STACK_DUMP
76 select HAVE_DEBUG_KMEMLEAK
77 select ANON_INODES
78 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
79 select HAVE_CMPXCHG_LOCAL
80 select HAVE_CMPXCHG_DOUBLE
81 select HAVE_ARCH_KMEMCHECK
82 select HAVE_USER_RETURN_NOTIFIER
83 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
84 select HAVE_ARCH_JUMP_LABEL
85 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
86 select SPARSE_IRQ
87 select GENERIC_FIND_FIRST_BIT
88 select GENERIC_IRQ_PROBE
89 select GENERIC_PENDING_IRQ if SMP
90 select GENERIC_IRQ_SHOW
91 select GENERIC_CLOCKEVENTS_MIN_ADJUST
92 select IRQ_FORCED_THREADING
93 select USE_GENERIC_SMP_HELPERS if SMP
94 select HAVE_BPF_JIT if X86_64
95 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
96 select CLKEVT_I8253
97 select ARCH_HAVE_NMI_SAFE_CMPXCHG
98 select GENERIC_IOMAP
99 select DCACHE_WORD_ACCESS
100 select GENERIC_SMP_IDLE_THREAD
101 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
102 select HAVE_ARCH_SECCOMP_FILTER
103 select BUILDTIME_EXTABLE_SORT
104 select GENERIC_CMOS_UPDATE
105 select HAVE_ARCH_SOFT_DIRTY
106 select CLOCKSOURCE_WATCHDOG
107 select GENERIC_CLOCKEVENTS
108 select ARCH_CLOCKSOURCE_DATA if X86_64
109 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
110 select GENERIC_TIME_VSYSCALL if X86_64
111 select KTIME_SCALAR if X86_32
112 select GENERIC_STRNCPY_FROM_USER
113 select GENERIC_STRNLEN_USER
114 select HAVE_CONTEXT_TRACKING if X86_64
115 select HAVE_IRQ_TIME_ACCOUNTING
116 select VIRT_TO_BUS
117 select MODULES_USE_ELF_REL if X86_32
118 select MODULES_USE_ELF_RELA if X86_64
119 select CLONE_BACKWARDS if X86_32
120 select ARCH_USE_BUILTIN_BSWAP
121 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
122 select OLD_SIGACTION if X86_32
123 select COMPAT_OLD_SIGACTION if IA32_EMULATION
124 select RTC_LIB
125 select HAVE_DEBUG_STACKOVERFLOW
126 select ARCH_SUPPORTS_ATOMIC_RMW
128 config INSTRUCTION_DECODER
129 def_bool y
130 depends on KPROBES || PERF_EVENTS || UPROBES
132 config OUTPUT_FORMAT
133 string
134 default "elf32-i386" if X86_32
135 default "elf64-x86-64" if X86_64
137 config ARCH_DEFCONFIG
138 string
139 default "arch/x86/configs/i386_defconfig" if X86_32
140 default "arch/x86/configs/x86_64_defconfig" if X86_64
142 config LOCKDEP_SUPPORT
143 def_bool y
145 config STACKTRACE_SUPPORT
146 def_bool y
148 config HAVE_LATENCYTOP_SUPPORT
149 def_bool y
151 config MMU
152 def_bool y
154 config SBUS
155 bool
157 config NEED_DMA_MAP_STATE
158 def_bool y
159 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
161 config NEED_SG_DMA_LENGTH
162 def_bool y
164 config GENERIC_ISA_DMA
165 def_bool y
166 depends on ISA_DMA_API
168 config GENERIC_BUG
169 def_bool y
170 depends on BUG
171 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
173 config GENERIC_BUG_RELATIVE_POINTERS
174 bool
176 config GENERIC_HWEIGHT
177 def_bool y
179 config ARCH_MAY_HAVE_PC_FDC
180 def_bool y
181 depends on ISA_DMA_API
183 config RWSEM_XCHGADD_ALGORITHM
184 def_bool y
186 config GENERIC_CALIBRATE_DELAY
187 def_bool y
189 config ARCH_HAS_CPU_RELAX
190 def_bool y
192 config ARCH_HAS_CACHE_LINE_SIZE
193 def_bool y
195 config ARCH_HAS_CPU_AUTOPROBE
196 def_bool y
198 config HAVE_SETUP_PER_CPU_AREA
199 def_bool y
201 config NEED_PER_CPU_EMBED_FIRST_CHUNK
202 def_bool y
204 config NEED_PER_CPU_PAGE_FIRST_CHUNK
205 def_bool y
207 config ARCH_HIBERNATION_POSSIBLE
208 def_bool y
210 config ARCH_SUSPEND_POSSIBLE
211 def_bool y
213 config ARCH_WANT_HUGE_PMD_SHARE
214 def_bool y
216 config ARCH_WANT_GENERAL_HUGETLB
217 def_bool y
219 config ZONE_DMA32
220 bool
221 default X86_64
223 config AUDIT_ARCH
224 bool
225 default X86_64
227 config ARCH_SUPPORTS_OPTIMIZED_INLINING
228 def_bool y
230 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
231 def_bool y
233 config HAVE_INTEL_TXT
234 def_bool y
235 depends on INTEL_IOMMU && ACPI
237 config X86_32_SMP
238 def_bool y
239 depends on X86_32 && SMP
241 config X86_64_SMP
242 def_bool y
243 depends on X86_64 && SMP
245 config X86_HT
246 def_bool y
247 depends on SMP
249 config X86_32_LAZY_GS
250 def_bool y
251 depends on X86_32 && !CC_STACKPROTECTOR
253 config ARCH_HWEIGHT_CFLAGS
254 string
255 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
256 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
258 config ARCH_CPU_PROBE_RELEASE
259 def_bool y
260 depends on HOTPLUG_CPU
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, like most personal computers, say N. If
285 you have a system with more than one CPU, say Y.
287 If you say N here, the kernel will run on single 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 singleprocessor machines. On a singleprocessor 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_WANT_INTEL_MID
445 bool "Intel MID platform support"
446 depends on X86_32
447 depends on X86_EXTENDED_PLATFORM
448 ---help---
449 Select to build a kernel capable of supporting Intel MID platform
450 systems which do not have the PCI legacy interfaces (Moorestown,
451 Medfield). If you are building for a PC class system say N here.
453 if X86_WANT_INTEL_MID
455 config X86_INTEL_MID
456 bool
458 config X86_MDFLD
459 bool "Medfield MID platform"
460 depends on PCI
461 depends on PCI_GOANY
462 depends on X86_IO_APIC
463 select X86_INTEL_MID
464 select SFI
465 select DW_APB_TIMER
466 select APB_TIMER
467 select I2C
468 select SPI
469 select INTEL_SCU_IPC
470 select X86_PLATFORM_DEVICES
471 select MFD_INTEL_MSIC
472 ---help---
473 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
474 Internet Device(MID) platform.
475 Unlike standard x86 PCs, Medfield does not have many legacy devices
476 nor standard legacy replacement devices/features. e.g. Medfield does
477 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
479 endif
481 config X86_INTEL_LPSS
482 bool "Intel Low Power Subsystem Support"
483 depends on ACPI
484 select COMMON_CLK
485 select PINCTRL
486 ---help---
487 Select to build support for Intel Low Power Subsystem such as
488 found on Intel Lynxpoint PCH. Selecting this option enables
489 things like clock tree (common clock framework) and pincontrol
490 which are needed by the LPSS peripheral drivers.
492 config X86_RDC321X
493 bool "RDC R-321x SoC"
494 depends on X86_32
495 depends on X86_EXTENDED_PLATFORM
496 select M486
497 select X86_REBOOTFIXUPS
498 ---help---
499 This option is needed for RDC R-321x system-on-chip, also known
500 as R-8610-(G).
501 If you don't have one of these chips, you should say N here.
503 config X86_32_NON_STANDARD
504 bool "Support non-standard 32-bit SMP architectures"
505 depends on X86_32 && SMP
506 depends on X86_EXTENDED_PLATFORM
507 ---help---
508 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
509 STA2X11, default subarchitectures. It is intended for a generic
510 binary kernel. If you select them all, kernel will probe it
511 one by one and will fallback to default.
513 # Alphabetically sorted list of Non standard 32 bit platforms
515 config X86_NUMAQ
516 bool "NUMAQ (IBM/Sequent)"
517 depends on X86_32_NON_STANDARD
518 depends on PCI
519 select NUMA
520 select X86_MPPARSE
521 ---help---
522 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
523 NUMA multiquad box. This changes the way that processors are
524 bootstrapped, and uses Clustered Logical APIC addressing mode instead
525 of Flat Logical. You will need a new lynxer.elf file to flash your
526 firmware with - send email to <Martin.Bligh@us.ibm.com>.
528 config X86_SUPPORTS_MEMORY_FAILURE
529 def_bool y
530 # MCE code calls memory_failure():
531 depends on X86_MCE
532 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
533 depends on !X86_NUMAQ
534 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
535 depends on X86_64 || !SPARSEMEM
536 select ARCH_SUPPORTS_MEMORY_FAILURE
538 config X86_VISWS
539 bool "SGI 320/540 (Visual Workstation)"
540 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
541 depends on X86_32_NON_STANDARD
542 ---help---
543 The SGI Visual Workstation series is an IA32-based workstation
544 based on SGI systems chips with some legacy PC hardware attached.
546 Say Y here to create a kernel to run on the SGI 320 or 540.
548 A kernel compiled for the Visual Workstation will run on general
549 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
551 config STA2X11
552 bool "STA2X11 Companion Chip Support"
553 depends on X86_32_NON_STANDARD && PCI
554 select X86_DEV_DMA_OPS
555 select X86_DMA_REMAP
556 select SWIOTLB
557 select MFD_STA2X11
558 select ARCH_REQUIRE_GPIOLIB
559 default n
560 ---help---
561 This adds support for boards based on the STA2X11 IO-Hub,
562 a.k.a. "ConneXt". The chip is used in place of the standard
563 PC chipset, so all "standard" peripherals are missing. If this
564 option is selected the kernel will still be able to boot on
565 standard PC machines.
567 config X86_SUMMIT
568 bool "Summit/EXA (IBM x440)"
569 depends on X86_32_NON_STANDARD
570 ---help---
571 This option is needed for IBM systems that use the Summit/EXA chipset.
572 In particular, it is needed for the x440.
574 config X86_ES7000
575 bool "Unisys ES7000 IA32 series"
576 depends on X86_32_NON_STANDARD && X86_BIGSMP
577 ---help---
578 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
579 supposed to run on an IA32-based Unisys ES7000 system.
581 config X86_32_IRIS
582 tristate "Eurobraille/Iris poweroff module"
583 depends on X86_32
584 ---help---
585 The Iris machines from EuroBraille do not have APM or ACPI support
586 to shut themselves down properly. A special I/O sequence is
587 needed to do so, which is what this module does at
588 kernel shutdown.
590 This is only for Iris machines from EuroBraille.
592 If unused, say N.
594 config SCHED_OMIT_FRAME_POINTER
595 def_bool y
596 prompt "Single-depth WCHAN output"
597 depends on X86
598 ---help---
599 Calculate simpler /proc/<PID>/wchan values. If this option
600 is disabled then wchan values will recurse back to the
601 caller function. This provides more accurate wchan values,
602 at the expense of slightly more scheduling overhead.
604 If in doubt, say "Y".
606 menuconfig HYPERVISOR_GUEST
607 bool "Linux guest support"
608 ---help---
609 Say Y here to enable options for running Linux under various hyper-
610 visors. This option enables basic hypervisor detection and platform
611 setup.
613 If you say N, all options in this submenu will be skipped and
614 disabled, and Linux guest support won't be built in.
616 if HYPERVISOR_GUEST
618 config PARAVIRT
619 bool "Enable paravirtualization code"
620 ---help---
621 This changes the kernel so it can modify itself when it is run
622 under a hypervisor, potentially improving performance significantly
623 over full virtualization. However, when run without a hypervisor
624 the kernel is theoretically slower and slightly larger.
626 config PARAVIRT_DEBUG
627 bool "paravirt-ops debugging"
628 depends on PARAVIRT && DEBUG_KERNEL
629 ---help---
630 Enable to debug paravirt_ops internals. Specifically, BUG if
631 a paravirt_op is missing when it is called.
633 config PARAVIRT_SPINLOCKS
634 bool "Paravirtualization layer for spinlocks"
635 depends on PARAVIRT && SMP
636 select UNINLINE_SPIN_UNLOCK
637 ---help---
638 Paravirtualized spinlocks allow a pvops backend to replace the
639 spinlock implementation with something virtualization-friendly
640 (for example, block the virtual CPU rather than spinning).
642 Unfortunately the downside is an up to 5% performance hit on
643 native kernels, with various workloads.
645 If you are unsure how to answer this question, answer N.
647 source "arch/x86/xen/Kconfig"
649 config KVM_GUEST
650 bool "KVM Guest support (including kvmclock)"
651 depends on PARAVIRT
652 select PARAVIRT_CLOCK
653 default y
654 ---help---
655 This option enables various optimizations for running under the KVM
656 hypervisor. It includes a paravirtualized clock, so that instead
657 of relying on a PIT (or probably other) emulation by the
658 underlying device model, the host provides the guest with
659 timing infrastructure such as time of day, and system time
661 config KVM_DEBUG_FS
662 bool "Enable debug information for KVM Guests in debugfs"
663 depends on KVM_GUEST && DEBUG_FS
664 default n
665 ---help---
666 This option enables collection of various statistics for KVM guest.
667 Statistics are displayed in debugfs filesystem. Enabling this option
668 may incur significant overhead.
670 source "arch/x86/lguest/Kconfig"
672 config PARAVIRT_TIME_ACCOUNTING
673 bool "Paravirtual steal time accounting"
674 depends on PARAVIRT
675 default n
676 ---help---
677 Select this option to enable fine granularity task steal time
678 accounting. Time spent executing other tasks in parallel with
679 the current vCPU is discounted from the vCPU power. To account for
680 that, there can be a small performance impact.
682 If in doubt, say N here.
684 config PARAVIRT_CLOCK
685 bool
687 endif #HYPERVISOR_GUEST
689 config NO_BOOTMEM
690 def_bool y
692 config MEMTEST
693 bool "Memtest"
694 ---help---
695 This option adds a kernel parameter 'memtest', which allows memtest
696 to be set.
697 memtest=0, mean disabled; -- default
698 memtest=1, mean do 1 test pattern;
699 ...
700 memtest=4, mean do 4 test patterns.
701 If you are unsure how to answer this question, answer N.
703 config X86_SUMMIT_NUMA
704 def_bool y
705 depends on X86_32 && NUMA && X86_32_NON_STANDARD
707 config X86_CYCLONE_TIMER
708 def_bool y
709 depends on X86_SUMMIT
711 source "arch/x86/Kconfig.cpu"
713 config HPET_TIMER
714 def_bool X86_64
715 prompt "HPET Timer Support" if X86_32
716 ---help---
717 Use the IA-PC HPET (High Precision Event Timer) to manage
718 time in preference to the PIT and RTC, if a HPET is
719 present.
720 HPET is the next generation timer replacing legacy 8254s.
721 The HPET provides a stable time base on SMP
722 systems, unlike the TSC, but it is more expensive to access,
723 as it is off-chip. You can find the HPET spec at
724 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
726 You can safely choose Y here. However, HPET will only be
727 activated if the platform and the BIOS support this feature.
728 Otherwise the 8254 will be used for timing services.
730 Choose N to continue using the legacy 8254 timer.
732 config HPET_EMULATE_RTC
733 def_bool y
734 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
736 config APB_TIMER
737 def_bool y if X86_INTEL_MID
738 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
739 select DW_APB_TIMER
740 depends on X86_INTEL_MID && SFI
741 help
742 APB timer is the replacement for 8254, HPET on X86 MID platforms.
743 The APBT provides a stable time base on SMP
744 systems, unlike the TSC, but it is more expensive to access,
745 as it is off-chip. APB timers are always running regardless of CPU
746 C states, they are used as per CPU clockevent device when possible.
748 # Mark as expert because too many people got it wrong.
749 # The code disables itself when not needed.
750 config DMI
751 default y
752 bool "Enable DMI scanning" if EXPERT
753 ---help---
754 Enabled scanning of DMI to identify machine quirks. Say Y
755 here unless you have verified that your setup is not
756 affected by entries in the DMI blacklist. Required by PNP
757 BIOS code.
759 config GART_IOMMU
760 bool "GART IOMMU support" if EXPERT
761 default y
762 select SWIOTLB
763 depends on X86_64 && PCI && AMD_NB
764 ---help---
765 Support for full DMA access of devices with 32bit memory access only
766 on systems with more than 3GB. This is usually needed for USB,
767 sound, many IDE/SATA chipsets and some other devices.
768 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
769 based hardware IOMMU and a software bounce buffer based IOMMU used
770 on Intel systems and as fallback.
771 The code is only active when needed (enough memory and limited
772 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
773 too.
775 config CALGARY_IOMMU
776 bool "IBM Calgary IOMMU support"
777 select SWIOTLB
778 depends on X86_64 && PCI
779 ---help---
780 Support for hardware IOMMUs in IBM's xSeries x366 and x460
781 systems. Needed to run systems with more than 3GB of memory
782 properly with 32-bit PCI devices that do not support DAC
783 (Double Address Cycle). Calgary also supports bus level
784 isolation, where all DMAs pass through the IOMMU. This
785 prevents them from going anywhere except their intended
786 destination. This catches hard-to-find kernel bugs and
787 mis-behaving drivers and devices that do not use the DMA-API
788 properly to set up their DMA buffers. The IOMMU can be
789 turned off at boot time with the iommu=off parameter.
790 Normally the kernel will make the right choice by itself.
791 If unsure, say Y.
793 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
794 def_bool y
795 prompt "Should Calgary be enabled by default?"
796 depends on CALGARY_IOMMU
797 ---help---
798 Should Calgary be enabled by default? if you choose 'y', Calgary
799 will be used (if it exists). If you choose 'n', Calgary will not be
800 used even if it exists. If you choose 'n' and would like to use
801 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
802 If unsure, say Y.
804 # need this always selected by IOMMU for the VIA workaround
805 config SWIOTLB
806 def_bool y if X86_64
807 ---help---
808 Support for software bounce buffers used on x86-64 systems
809 which don't have a hardware IOMMU. Using this PCI devices
810 which can only access 32-bits of memory can be used on systems
811 with more than 3 GB of memory.
812 If unsure, say Y.
814 config IOMMU_HELPER
815 def_bool y
816 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
818 config MAXSMP
819 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
820 depends on X86_64 && SMP && DEBUG_KERNEL
821 select CPUMASK_OFFSTACK
822 ---help---
823 Enable maximum number of CPUS and NUMA Nodes for this architecture.
824 If unsure, say N.
826 config NR_CPUS
827 int "Maximum number of CPUs" if SMP && !MAXSMP
828 range 2 8 if SMP && X86_32 && !X86_BIGSMP
829 range 2 512 if SMP && !MAXSMP
830 default "1" if !SMP
831 default "4096" if MAXSMP
832 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
833 default "8" if SMP
834 ---help---
835 This allows you to specify the maximum number of CPUs which this
836 kernel will support. The maximum supported value is 512 and the
837 minimum value which makes sense is 2.
839 This is purely to save memory - each supported CPU adds
840 approximately eight kilobytes to the kernel image.
842 config SCHED_SMT
843 bool "SMT (Hyperthreading) scheduler support"
844 depends on X86_HT
845 ---help---
846 SMT scheduler support improves the CPU scheduler's decision making
847 when dealing with Intel Pentium 4 chips with HyperThreading at a
848 cost of slightly increased overhead in some places. If unsure say
849 N here.
851 config SCHED_MC
852 def_bool y
853 prompt "Multi-core scheduler support"
854 depends on X86_HT
855 ---help---
856 Multi-core scheduler support improves the CPU scheduler's decision
857 making when dealing with multi-core CPU chips at a cost of slightly
858 increased overhead in some places. If unsure say N here.
860 source "kernel/Kconfig.preempt"
862 config X86_UP_APIC
863 bool "Local APIC support on uniprocessors"
864 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
865 ---help---
866 A local APIC (Advanced Programmable Interrupt Controller) is an
867 integrated interrupt controller in the CPU. If you have a single-CPU
868 system which has a processor with a local APIC, you can say Y here to
869 enable and use it. If you say Y here even though your machine doesn't
870 have a local APIC, then the kernel will still run with no slowdown at
871 all. The local APIC supports CPU-generated self-interrupts (timer,
872 performance counters), and the NMI watchdog which detects hard
873 lockups.
875 config X86_UP_IOAPIC
876 bool "IO-APIC support on uniprocessors"
877 depends on X86_UP_APIC
878 ---help---
879 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
880 SMP-capable replacement for PC-style interrupt controllers. Most
881 SMP systems and many recent uniprocessor systems have one.
883 If you have a single-CPU system with an IO-APIC, you can say Y here
884 to use it. If you say Y here even though your machine doesn't have
885 an IO-APIC, then the kernel will still run with no slowdown at all.
887 config X86_LOCAL_APIC
888 def_bool y
889 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
891 config X86_IO_APIC
892 def_bool y
893 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
895 config X86_VISWS_APIC
896 def_bool y
897 depends on X86_32 && X86_VISWS
899 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
900 bool "Reroute for broken boot IRQs"
901 depends on X86_IO_APIC
902 ---help---
903 This option enables a workaround that fixes a source of
904 spurious interrupts. This is recommended when threaded
905 interrupt handling is used on systems where the generation of
906 superfluous "boot interrupts" cannot be disabled.
908 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
909 entry in the chipset's IO-APIC is masked (as, e.g. the RT
910 kernel does during interrupt handling). On chipsets where this
911 boot IRQ generation cannot be disabled, this workaround keeps
912 the original IRQ line masked so that only the equivalent "boot
913 IRQ" is delivered to the CPUs. The workaround also tells the
914 kernel to set up the IRQ handler on the boot IRQ line. In this
915 way only one interrupt is delivered to the kernel. Otherwise
916 the spurious second interrupt may cause the kernel to bring
917 down (vital) interrupt lines.
919 Only affects "broken" chipsets. Interrupt sharing may be
920 increased on these systems.
922 config X86_MCE
923 bool "Machine Check / overheating reporting"
924 default y
925 ---help---
926 Machine Check support allows the processor to notify the
927 kernel if it detects a problem (e.g. overheating, data corruption).
928 The action the kernel takes depends on the severity of the problem,
929 ranging from warning messages to halting the machine.
931 config X86_MCE_INTEL
932 def_bool y
933 prompt "Intel MCE features"
934 depends on X86_MCE && X86_LOCAL_APIC
935 ---help---
936 Additional support for intel specific MCE features such as
937 the thermal monitor.
939 config X86_MCE_AMD
940 def_bool y
941 prompt "AMD MCE features"
942 depends on X86_MCE && X86_LOCAL_APIC
943 ---help---
944 Additional support for AMD specific MCE features such as
945 the DRAM Error Threshold.
947 config X86_ANCIENT_MCE
948 bool "Support for old Pentium 5 / WinChip machine checks"
949 depends on X86_32 && X86_MCE
950 ---help---
951 Include support for machine check handling on old Pentium 5 or WinChip
952 systems. These typically need to be enabled explicitely on the command
953 line.
955 config X86_MCE_THRESHOLD
956 depends on X86_MCE_AMD || X86_MCE_INTEL
957 def_bool y
959 config X86_MCE_INJECT
960 depends on X86_MCE
961 tristate "Machine check injector support"
962 ---help---
963 Provide support for injecting machine checks for testing purposes.
964 If you don't know what a machine check is and you don't do kernel
965 QA it is safe to say n.
967 config X86_THERMAL_VECTOR
968 def_bool y
969 depends on X86_MCE_INTEL
971 config VM86
972 bool "Enable VM86 support" if EXPERT
973 default y
974 depends on X86_32
975 ---help---
976 This option is required by programs like DOSEMU to run
977 16-bit real mode legacy code on x86 processors. It also may
978 be needed by software like XFree86 to initialize some video
979 cards via BIOS. Disabling this option saves about 6K.
981 config X86_16BIT
982 bool "Enable support for 16-bit segments" if EXPERT
983 default y
984 ---help---
985 This option is required by programs like Wine to run 16-bit
986 protected mode legacy code on x86 processors. Disabling
987 this option saves about 300 bytes on i386, or around 6K text
988 plus 16K runtime memory on x86-64,
990 config X86_ESPFIX32
991 def_bool y
992 depends on X86_16BIT && X86_32
994 config X86_ESPFIX64
995 def_bool y
996 depends on X86_16BIT && X86_64
998 config TOSHIBA
999 tristate "Toshiba Laptop support"
1000 depends on X86_32
1001 ---help---
1002 This adds a driver to safely access the System Management Mode of
1003 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1004 not work on models with a Phoenix BIOS. The System Management Mode
1005 is used to set the BIOS and power saving options on Toshiba portables.
1007 For information on utilities to make use of this driver see the
1008 Toshiba Linux utilities web site at:
1009 <http://www.buzzard.org.uk/toshiba/>.
1011 Say Y if you intend to run this kernel on a Toshiba portable.
1012 Say N otherwise.
1014 config I8K
1015 tristate "Dell laptop support"
1016 select HWMON
1017 ---help---
1018 This adds a driver to safely access the System Management Mode
1019 of the CPU on the Dell Inspiron 8000. The System Management Mode
1020 is used to read cpu temperature and cooling fan status and to
1021 control the fans on the I8K portables.
1023 This driver has been tested only on the Inspiron 8000 but it may
1024 also work with other Dell laptops. You can force loading on other
1025 models by passing the parameter `force=1' to the module. Use at
1026 your own risk.
1028 For information on utilities to make use of this driver see the
1029 I8K Linux utilities web site at:
1030 <http://people.debian.org/~dz/i8k/>
1032 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1033 Say N otherwise.
1035 config X86_REBOOTFIXUPS
1036 bool "Enable X86 board specific fixups for reboot"
1037 depends on X86_32
1038 ---help---
1039 This enables chipset and/or board specific fixups to be done
1040 in order to get reboot to work correctly. This is only needed on
1041 some combinations of hardware and BIOS. The symptom, for which
1042 this config is intended, is when reboot ends with a stalled/hung
1043 system.
1045 Currently, the only fixup is for the Geode machines using
1046 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1048 Say Y if you want to enable the fixup. Currently, it's safe to
1049 enable this option even if you don't need it.
1050 Say N otherwise.
1052 config MICROCODE
1053 tristate "CPU microcode loading support"
1054 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1055 select FW_LOADER
1056 ---help---
1058 If you say Y here, you will be able to update the microcode on
1059 certain Intel and AMD processors. The Intel support is for the
1060 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1061 Xeon etc. The AMD support is for families 0x10 and later. You will
1062 obviously need the actual microcode binary data itself which is not
1063 shipped with the Linux kernel.
1065 This option selects the general module only, you need to select
1066 at least one vendor specific module as well.
1068 To compile this driver as a module, choose M here: the module
1069 will be called microcode.
1071 config MICROCODE_INTEL
1072 bool "Intel microcode loading support"
1073 depends on MICROCODE
1074 default MICROCODE
1075 select FW_LOADER
1076 ---help---
1077 This options enables microcode patch loading support for Intel
1078 processors.
1080 For latest news and information on obtaining all the required
1081 Intel ingredients for this driver, check:
1082 <http://www.urbanmyth.org/microcode/>.
1084 config MICROCODE_AMD
1085 bool "AMD microcode loading support"
1086 depends on MICROCODE
1087 select FW_LOADER
1088 ---help---
1089 If you select this option, microcode patch loading support for AMD
1090 processors will be enabled.
1092 config MICROCODE_OLD_INTERFACE
1093 def_bool y
1094 depends on MICROCODE
1096 config MICROCODE_INTEL_LIB
1097 def_bool y
1098 depends on MICROCODE_INTEL
1100 config MICROCODE_INTEL_EARLY
1101 def_bool n
1103 config MICROCODE_AMD_EARLY
1104 def_bool n
1106 config MICROCODE_EARLY
1107 bool "Early load microcode"
1108 depends on MICROCODE=y && BLK_DEV_INITRD
1109 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1110 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1111 default y
1112 help
1113 This option provides functionality to read additional microcode data
1114 at the beginning of initrd image. The data tells kernel to load
1115 microcode to CPU's as early as possible. No functional change if no
1116 microcode data is glued to the initrd, therefore it's safe to say Y.
1118 config X86_MSR
1119 tristate "/dev/cpu/*/msr - Model-specific register support"
1120 ---help---
1121 This device gives privileged processes access to the x86
1122 Model-Specific Registers (MSRs). It is a character device with
1123 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1124 MSR accesses are directed to a specific CPU on multi-processor
1125 systems.
1127 config X86_CPUID
1128 tristate "/dev/cpu/*/cpuid - CPU information support"
1129 ---help---
1130 This device gives processes access to the x86 CPUID instruction to
1131 be executed on a specific processor. It is a character device
1132 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1133 /dev/cpu/31/cpuid.
1135 choice
1136 prompt "High Memory Support"
1137 default HIGHMEM64G if X86_NUMAQ
1138 default HIGHMEM4G
1139 depends on X86_32
1141 config NOHIGHMEM
1142 bool "off"
1143 depends on !X86_NUMAQ
1144 ---help---
1145 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1146 However, the address space of 32-bit x86 processors is only 4
1147 Gigabytes large. That means that, if you have a large amount of
1148 physical memory, not all of it can be "permanently mapped" by the
1149 kernel. The physical memory that's not permanently mapped is called
1150 "high memory".
1152 If you are compiling a kernel which will never run on a machine with
1153 more than 1 Gigabyte total physical RAM, answer "off" here (default
1154 choice and suitable for most users). This will result in a "3GB/1GB"
1155 split: 3GB are mapped so that each process sees a 3GB virtual memory
1156 space and the remaining part of the 4GB virtual memory space is used
1157 by the kernel to permanently map as much physical memory as
1158 possible.
1160 If the machine has between 1 and 4 Gigabytes physical RAM, then
1161 answer "4GB" here.
1163 If more than 4 Gigabytes is used then answer "64GB" here. This
1164 selection turns Intel PAE (Physical Address Extension) mode on.
1165 PAE implements 3-level paging on IA32 processors. PAE is fully
1166 supported by Linux, PAE mode is implemented on all recent Intel
1167 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1168 then the kernel will not boot on CPUs that don't support PAE!
1170 The actual amount of total physical memory will either be
1171 auto detected or can be forced by using a kernel command line option
1172 such as "mem=256M". (Try "man bootparam" or see the documentation of
1173 your boot loader (lilo or loadlin) about how to pass options to the
1174 kernel at boot time.)
1176 If unsure, say "off".
1178 config HIGHMEM4G
1179 bool "4GB"
1180 depends on !X86_NUMAQ
1181 ---help---
1182 Select this if you have a 32-bit processor and between 1 and 4
1183 gigabytes of physical RAM.
1185 config HIGHMEM64G
1186 bool "64GB"
1187 depends on !M486
1188 select X86_PAE
1189 ---help---
1190 Select this if you have a 32-bit processor and more than 4
1191 gigabytes of physical RAM.
1193 endchoice
1195 choice
1196 prompt "Memory split" if EXPERT
1197 default VMSPLIT_3G
1198 depends on X86_32
1199 ---help---
1200 Select the desired split between kernel and user memory.
1202 If the address range available to the kernel is less than the
1203 physical memory installed, the remaining memory will be available
1204 as "high memory". Accessing high memory is a little more costly
1205 than low memory, as it needs to be mapped into the kernel first.
1206 Note that increasing the kernel address space limits the range
1207 available to user programs, making the address space there
1208 tighter. Selecting anything other than the default 3G/1G split
1209 will also likely make your kernel incompatible with binary-only
1210 kernel modules.
1212 If you are not absolutely sure what you are doing, leave this
1213 option alone!
1215 config VMSPLIT_3G
1216 bool "3G/1G user/kernel split"
1217 config VMSPLIT_3G_OPT
1218 depends on !X86_PAE
1219 bool "3G/1G user/kernel split (for full 1G low memory)"
1220 config VMSPLIT_2G
1221 bool "2G/2G user/kernel split"
1222 config VMSPLIT_2G_OPT
1223 depends on !X86_PAE
1224 bool "2G/2G user/kernel split (for full 2G low memory)"
1225 config VMSPLIT_1G
1226 bool "1G/3G user/kernel split"
1227 endchoice
1229 config PAGE_OFFSET
1230 hex
1231 default 0xB0000000 if VMSPLIT_3G_OPT
1232 default 0x80000000 if VMSPLIT_2G
1233 default 0x78000000 if VMSPLIT_2G_OPT
1234 default 0x40000000 if VMSPLIT_1G
1235 default 0xC0000000
1236 depends on X86_32
1238 config HIGHMEM
1239 def_bool y
1240 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1242 config X86_PAE
1243 bool "PAE (Physical Address Extension) Support"
1244 depends on X86_32 && !HIGHMEM4G
1245 ---help---
1246 PAE is required for NX support, and furthermore enables
1247 larger swapspace support for non-overcommit purposes. It
1248 has the cost of more pagetable lookup overhead, and also
1249 consumes more pagetable space per process.
1251 config ARCH_PHYS_ADDR_T_64BIT
1252 def_bool y
1253 depends on X86_64 || X86_PAE
1255 config ARCH_DMA_ADDR_T_64BIT
1256 def_bool y
1257 depends on X86_64 || HIGHMEM64G
1259 config DIRECT_GBPAGES
1260 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1261 default y
1262 depends on X86_64
1263 ---help---
1264 Allow the kernel linear mapping to use 1GB pages on CPUs that
1265 support it. This can improve the kernel's performance a tiny bit by
1266 reducing TLB pressure. If in doubt, say "Y".
1268 # Common NUMA Features
1269 config NUMA
1270 bool "Numa Memory Allocation and Scheduler Support"
1271 depends on SMP
1272 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1273 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1274 ---help---
1275 Enable NUMA (Non Uniform Memory Access) support.
1277 The kernel will try to allocate memory used by a CPU on the
1278 local memory controller of the CPU and add some more
1279 NUMA awareness to the kernel.
1281 For 64-bit this is recommended if the system is Intel Core i7
1282 (or later), AMD Opteron, or EM64T NUMA.
1284 For 32-bit this is only needed on (rare) 32-bit-only platforms
1285 that support NUMA topologies, such as NUMAQ / Summit, or if you
1286 boot a 32-bit kernel on a 64-bit NUMA platform.
1288 Otherwise, you should say N.
1290 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1291 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1293 config AMD_NUMA
1294 def_bool y
1295 prompt "Old style AMD Opteron NUMA detection"
1296 depends on X86_64 && NUMA && PCI
1297 ---help---
1298 Enable AMD NUMA node topology detection. You should say Y here if
1299 you have a multi processor AMD system. This uses an old method to
1300 read the NUMA configuration directly from the builtin Northbridge
1301 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1302 which also takes priority if both are compiled in.
1304 config X86_64_ACPI_NUMA
1305 def_bool y
1306 prompt "ACPI NUMA detection"
1307 depends on X86_64 && NUMA && ACPI && PCI
1308 select ACPI_NUMA
1309 ---help---
1310 Enable ACPI SRAT based node topology detection.
1312 # Some NUMA nodes have memory ranges that span
1313 # other nodes. Even though a pfn is valid and
1314 # between a node's start and end pfns, it may not
1315 # reside on that node. See memmap_init_zone()
1316 # for details.
1317 config NODES_SPAN_OTHER_NODES
1318 def_bool y
1319 depends on X86_64_ACPI_NUMA
1321 config NUMA_EMU
1322 bool "NUMA emulation"
1323 depends on NUMA
1324 ---help---
1325 Enable NUMA emulation. A flat machine will be split
1326 into virtual nodes when booted with "numa=fake=N", where N is the
1327 number of nodes. This is only useful for debugging.
1329 config NODES_SHIFT
1330 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1331 range 1 10
1332 default "10" if MAXSMP
1333 default "6" if X86_64
1334 default "4" if X86_NUMAQ
1335 default "3"
1336 depends on NEED_MULTIPLE_NODES
1337 ---help---
1338 Specify the maximum number of NUMA Nodes available on the target
1339 system. Increases memory reserved to accommodate various tables.
1341 config ARCH_HAVE_MEMORY_PRESENT
1342 def_bool y
1343 depends on X86_32 && DISCONTIGMEM
1345 config NEED_NODE_MEMMAP_SIZE
1346 def_bool y
1347 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1349 config ARCH_FLATMEM_ENABLE
1350 def_bool y
1351 depends on X86_32 && !NUMA
1353 config ARCH_DISCONTIGMEM_ENABLE
1354 def_bool y
1355 depends on NUMA && X86_32
1357 config ARCH_DISCONTIGMEM_DEFAULT
1358 def_bool y
1359 depends on NUMA && X86_32
1361 config ARCH_SPARSEMEM_ENABLE
1362 def_bool y
1363 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1364 select SPARSEMEM_STATIC if X86_32
1365 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1367 config ARCH_SPARSEMEM_DEFAULT
1368 def_bool y
1369 depends on X86_64
1371 config ARCH_SELECT_MEMORY_MODEL
1372 def_bool y
1373 depends on ARCH_SPARSEMEM_ENABLE
1375 config ARCH_MEMORY_PROBE
1376 bool "Enable sysfs memory/probe interface"
1377 depends on X86_64 && MEMORY_HOTPLUG
1378 help
1379 This option enables a sysfs memory/probe interface for testing.
1380 See Documentation/memory-hotplug.txt for more information.
1381 If you are unsure how to answer this question, answer N.
1383 config ARCH_PROC_KCORE_TEXT
1384 def_bool y
1385 depends on X86_64 && PROC_KCORE
1387 config ILLEGAL_POINTER_VALUE
1388 hex
1389 default 0 if X86_32
1390 default 0xdead000000000000 if X86_64
1392 source "mm/Kconfig"
1394 config HIGHPTE
1395 bool "Allocate 3rd-level pagetables from highmem"
1396 depends on HIGHMEM
1397 ---help---
1398 The VM uses one page table entry for each page of physical memory.
1399 For systems with a lot of RAM, this can be wasteful of precious
1400 low memory. Setting this option will put user-space page table
1401 entries in high memory.
1403 config X86_CHECK_BIOS_CORRUPTION
1404 bool "Check for low memory corruption"
1405 ---help---
1406 Periodically check for memory corruption in low memory, which
1407 is suspected to be caused by BIOS. Even when enabled in the
1408 configuration, it is disabled at runtime. Enable it by
1409 setting "memory_corruption_check=1" on the kernel command
1410 line. By default it scans the low 64k of memory every 60
1411 seconds; see the memory_corruption_check_size and
1412 memory_corruption_check_period parameters in
1413 Documentation/kernel-parameters.txt to adjust this.
1415 When enabled with the default parameters, this option has
1416 almost no overhead, as it reserves a relatively small amount
1417 of memory and scans it infrequently. It both detects corruption
1418 and prevents it from affecting the running system.
1420 It is, however, intended as a diagnostic tool; if repeatable
1421 BIOS-originated corruption always affects the same memory,
1422 you can use memmap= to prevent the kernel from using that
1423 memory.
1425 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1426 bool "Set the default setting of memory_corruption_check"
1427 depends on X86_CHECK_BIOS_CORRUPTION
1428 default y
1429 ---help---
1430 Set whether the default state of memory_corruption_check is
1431 on or off.
1433 config X86_RESERVE_LOW
1434 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1435 default 64
1436 range 4 640
1437 ---help---
1438 Specify the amount of low memory to reserve for the BIOS.
1440 The first page contains BIOS data structures that the kernel
1441 must not use, so that page must always be reserved.
1443 By default we reserve the first 64K of physical RAM, as a
1444 number of BIOSes are known to corrupt that memory range
1445 during events such as suspend/resume or monitor cable
1446 insertion, so it must not be used by the kernel.
1448 You can set this to 4 if you are absolutely sure that you
1449 trust the BIOS to get all its memory reservations and usages
1450 right. If you know your BIOS have problems beyond the
1451 default 64K area, you can set this to 640 to avoid using the
1452 entire low memory range.
1454 If you have doubts about the BIOS (e.g. suspend/resume does
1455 not work or there's kernel crashes after certain hardware
1456 hotplug events) then you might want to enable
1457 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1458 typical corruption patterns.
1460 Leave this to the default value of 64 if you are unsure.
1462 config MATH_EMULATION
1463 bool
1464 prompt "Math emulation" if X86_32
1465 ---help---
1466 Linux can emulate a math coprocessor (used for floating point
1467 operations) if you don't have one. 486DX and Pentium processors have
1468 a math coprocessor built in, 486SX and 386 do not, unless you added
1469 a 487DX or 387, respectively. (The messages during boot time can
1470 give you some hints here ["man dmesg"].) Everyone needs either a
1471 coprocessor or this emulation.
1473 If you don't have a math coprocessor, you need to say Y here; if you
1474 say Y here even though you have a coprocessor, the coprocessor will
1475 be used nevertheless. (This behavior can be changed with the kernel
1476 command line option "no387", which comes handy if your coprocessor
1477 is broken. Try "man bootparam" or see the documentation of your boot
1478 loader (lilo or loadlin) about how to pass options to the kernel at
1479 boot time.) This means that it is a good idea to say Y here if you
1480 intend to use this kernel on different machines.
1482 More information about the internals of the Linux math coprocessor
1483 emulation can be found in <file:arch/x86/math-emu/README>.
1485 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1486 kernel, it won't hurt.
1488 config MTRR
1489 def_bool y
1490 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1491 ---help---
1492 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1493 the Memory Type Range Registers (MTRRs) may be used to control
1494 processor access to memory ranges. This is most useful if you have
1495 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1496 allows bus write transfers to be combined into a larger transfer
1497 before bursting over the PCI/AGP bus. This can increase performance
1498 of image write operations 2.5 times or more. Saying Y here creates a
1499 /proc/mtrr file which may be used to manipulate your processor's
1500 MTRRs. Typically the X server should use this.
1502 This code has a reasonably generic interface so that similar
1503 control registers on other processors can be easily supported
1504 as well:
1506 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1507 Registers (ARRs) which provide a similar functionality to MTRRs. For
1508 these, the ARRs are used to emulate the MTRRs.
1509 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1510 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1511 write-combining. All of these processors are supported by this code
1512 and it makes sense to say Y here if you have one of them.
1514 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1515 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1516 can lead to all sorts of problems, so it's good to say Y here.
1518 You can safely say Y even if your machine doesn't have MTRRs, you'll
1519 just add about 9 KB to your kernel.
1521 See <file:Documentation/x86/mtrr.txt> for more information.
1523 config MTRR_SANITIZER
1524 def_bool y
1525 prompt "MTRR cleanup support"
1526 depends on MTRR
1527 ---help---
1528 Convert MTRR layout from continuous to discrete, so X drivers can
1529 add writeback entries.
1531 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1532 The largest mtrr entry size for a continuous block can be set with
1533 mtrr_chunk_size.
1535 If unsure, say Y.
1537 config MTRR_SANITIZER_ENABLE_DEFAULT
1538 int "MTRR cleanup enable value (0-1)"
1539 range 0 1
1540 default "0"
1541 depends on MTRR_SANITIZER
1542 ---help---
1543 Enable mtrr cleanup default value
1545 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1546 int "MTRR cleanup spare reg num (0-7)"
1547 range 0 7
1548 default "1"
1549 depends on MTRR_SANITIZER
1550 ---help---
1551 mtrr cleanup spare entries default, it can be changed via
1552 mtrr_spare_reg_nr=N on the kernel command line.
1554 config X86_PAT
1555 def_bool y
1556 prompt "x86 PAT support" if EXPERT
1557 depends on MTRR
1558 ---help---
1559 Use PAT attributes to setup page level cache control.
1561 PATs are the modern equivalents of MTRRs and are much more
1562 flexible than MTRRs.
1564 Say N here if you see bootup problems (boot crash, boot hang,
1565 spontaneous reboots) or a non-working video driver.
1567 If unsure, say Y.
1569 config ARCH_USES_PG_UNCACHED
1570 def_bool y
1571 depends on X86_PAT
1573 config ARCH_RANDOM
1574 def_bool y
1575 prompt "x86 architectural random number generator" if EXPERT
1576 ---help---
1577 Enable the x86 architectural RDRAND instruction
1578 (Intel Bull Mountain technology) to generate random numbers.
1579 If supported, this is a high bandwidth, cryptographically
1580 secure hardware random number generator.
1582 config X86_SMAP
1583 def_bool y
1584 prompt "Supervisor Mode Access Prevention" if EXPERT
1585 ---help---
1586 Supervisor Mode Access Prevention (SMAP) is a security
1587 feature in newer Intel processors. There is a small
1588 performance cost if this enabled and turned on; there is
1589 also a small increase in the kernel size if this is enabled.
1591 If unsure, say Y.
1593 config EFI
1594 bool "EFI runtime service support"
1595 depends on ACPI
1596 select UCS2_STRING
1597 ---help---
1598 This enables the kernel to use EFI runtime services that are
1599 available (such as the EFI variable services).
1601 This option is only useful on systems that have EFI firmware.
1602 In addition, you should use the latest ELILO loader available
1603 at <http://elilo.sourceforge.net> in order to take advantage
1604 of EFI runtime services. However, even with this option, the
1605 resultant kernel should continue to boot on existing non-EFI
1606 platforms.
1608 config EFI_STUB
1609 bool "EFI stub support"
1610 depends on EFI
1611 select RELOCATABLE
1612 ---help---
1613 This kernel feature allows a bzImage to be loaded directly
1614 by EFI firmware without the use of a bootloader.
1616 See Documentation/x86/efi-stub.txt for more information.
1618 config SECCOMP
1619 def_bool y
1620 prompt "Enable seccomp to safely compute untrusted bytecode"
1621 ---help---
1622 This kernel feature is useful for number crunching applications
1623 that may need to compute untrusted bytecode during their
1624 execution. By using pipes or other transports made available to
1625 the process as file descriptors supporting the read/write
1626 syscalls, it's possible to isolate those applications in
1627 their own address space using seccomp. Once seccomp is
1628 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1629 and the task is only allowed to execute a few safe syscalls
1630 defined by each seccomp mode.
1632 If unsure, say Y. Only embedded should say N here.
1634 config CC_STACKPROTECTOR
1635 bool "Enable -fstack-protector buffer overflow detection"
1636 ---help---
1637 This option turns on the -fstack-protector GCC feature. This
1638 feature puts, at the beginning of functions, a canary value on
1639 the stack just before the return address, and validates
1640 the value just before actually returning. Stack based buffer
1641 overflows (that need to overwrite this return address) now also
1642 overwrite the canary, which gets detected and the attack is then
1643 neutralized via a kernel panic.
1645 This feature requires gcc version 4.2 or above, or a distribution
1646 gcc with the feature backported. Older versions are automatically
1647 detected and for those versions, this configuration option is
1648 ignored. (and a warning is printed during bootup)
1650 source kernel/Kconfig.hz
1652 config KEXEC
1653 bool "kexec system call"
1654 ---help---
1655 kexec is a system call that implements the ability to shutdown your
1656 current kernel, and to start another kernel. It is like a reboot
1657 but it is independent of the system firmware. And like a reboot
1658 you can start any kernel with it, not just Linux.
1660 The name comes from the similarity to the exec system call.
1662 It is an ongoing process to be certain the hardware in a machine
1663 is properly shutdown, so do not be surprised if this code does not
1664 initially work for you. As of this writing the exact hardware
1665 interface is strongly in flux, so no good recommendation can be
1666 made.
1668 config CRASH_DUMP
1669 bool "kernel crash dumps"
1670 depends on X86_64 || (X86_32 && HIGHMEM)
1671 ---help---
1672 Generate crash dump after being started by kexec.
1673 This should be normally only set in special crash dump kernels
1674 which are loaded in the main kernel with kexec-tools into
1675 a specially reserved region and then later executed after
1676 a crash by kdump/kexec. The crash dump kernel must be compiled
1677 to a memory address not used by the main kernel or BIOS using
1678 PHYSICAL_START, or it must be built as a relocatable image
1679 (CONFIG_RELOCATABLE=y).
1680 For more details see Documentation/kdump/kdump.txt
1682 config KEXEC_JUMP
1683 bool "kexec jump"
1684 depends on KEXEC && HIBERNATION
1685 ---help---
1686 Jump between original kernel and kexeced kernel and invoke
1687 code in physical address mode via KEXEC
1689 config PHYSICAL_START
1690 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1691 default "0x1000000"
1692 ---help---
1693 This gives the physical address where the kernel is loaded.
1695 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1696 bzImage will decompress itself to above physical address and
1697 run from there. Otherwise, bzImage will run from the address where
1698 it has been loaded by the boot loader and will ignore above physical
1699 address.
1701 In normal kdump cases one does not have to set/change this option
1702 as now bzImage can be compiled as a completely relocatable image
1703 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1704 address. This option is mainly useful for the folks who don't want
1705 to use a bzImage for capturing the crash dump and want to use a
1706 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1707 to be specifically compiled to run from a specific memory area
1708 (normally a reserved region) and this option comes handy.
1710 So if you are using bzImage for capturing the crash dump,
1711 leave the value here unchanged to 0x1000000 and set
1712 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1713 for capturing the crash dump change this value to start of
1714 the reserved region. In other words, it can be set based on
1715 the "X" value as specified in the "crashkernel=YM@XM"
1716 command line boot parameter passed to the panic-ed
1717 kernel. Please take a look at Documentation/kdump/kdump.txt
1718 for more details about crash dumps.
1720 Usage of bzImage for capturing the crash dump is recommended as
1721 one does not have to build two kernels. Same kernel can be used
1722 as production kernel and capture kernel. Above option should have
1723 gone away after relocatable bzImage support is introduced. But it
1724 is present because there are users out there who continue to use
1725 vmlinux for dump capture. This option should go away down the
1726 line.
1728 Don't change this unless you know what you are doing.
1730 config RELOCATABLE
1731 bool "Build a relocatable kernel"
1732 default y
1733 ---help---
1734 This builds a kernel image that retains relocation information
1735 so it can be loaded someplace besides the default 1MB.
1736 The relocations tend to make the kernel binary about 10% larger,
1737 but are discarded at runtime.
1739 One use is for the kexec on panic case where the recovery kernel
1740 must live at a different physical address than the primary
1741 kernel.
1743 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1744 it has been loaded at and the compile time physical address
1745 (CONFIG_PHYSICAL_START) is ignored.
1747 # Relocation on x86-32 needs some additional build support
1748 config X86_NEED_RELOCS
1749 def_bool y
1750 depends on X86_32 && RELOCATABLE
1752 config PHYSICAL_ALIGN
1753 hex "Alignment value to which kernel should be aligned"
1754 default "0x1000000"
1755 range 0x2000 0x1000000 if X86_32
1756 range 0x200000 0x1000000 if X86_64
1757 ---help---
1758 This value puts the alignment restrictions on physical address
1759 where kernel is loaded and run from. Kernel is compiled for an
1760 address which meets above alignment restriction.
1762 If bootloader loads the kernel at a non-aligned address and
1763 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1764 address aligned to above value and run from there.
1766 If bootloader loads the kernel at a non-aligned address and
1767 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1768 load address and decompress itself to the address it has been
1769 compiled for and run from there. The address for which kernel is
1770 compiled already meets above alignment restrictions. Hence the
1771 end result is that kernel runs from a physical address meeting
1772 above alignment restrictions.
1774 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1775 this value must be a multiple of 0x200000.
1777 Don't change this unless you know what you are doing.
1779 config HOTPLUG_CPU
1780 bool "Support for hot-pluggable CPUs"
1781 depends on SMP
1782 ---help---
1783 Say Y here to allow turning CPUs off and on. CPUs can be
1784 controlled through /sys/devices/system/cpu.
1785 ( Note: power management support will enable this option
1786 automatically on SMP systems. )
1787 Say N if you want to disable CPU hotplug.
1789 config BOOTPARAM_HOTPLUG_CPU0
1790 bool "Set default setting of cpu0_hotpluggable"
1791 default n
1792 depends on HOTPLUG_CPU
1793 ---help---
1794 Set whether default state of cpu0_hotpluggable is on or off.
1796 Say Y here to enable CPU0 hotplug by default. If this switch
1797 is turned on, there is no need to give cpu0_hotplug kernel
1798 parameter and the CPU0 hotplug feature is enabled by default.
1800 Please note: there are two known CPU0 dependencies if you want
1801 to enable the CPU0 hotplug feature either by this switch or by
1802 cpu0_hotplug kernel parameter.
1804 First, resume from hibernate or suspend always starts from CPU0.
1805 So hibernate and suspend are prevented if CPU0 is offline.
1807 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1808 offline if any interrupt can not migrate out of CPU0. There may
1809 be other CPU0 dependencies.
1811 Please make sure the dependencies are under your control before
1812 you enable this feature.
1814 Say N if you don't want to enable CPU0 hotplug feature by default.
1815 You still can enable the CPU0 hotplug feature at boot by kernel
1816 parameter cpu0_hotplug.
1818 config DEBUG_HOTPLUG_CPU0
1819 def_bool n
1820 prompt "Debug CPU0 hotplug"
1821 depends on HOTPLUG_CPU
1822 ---help---
1823 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1824 soon as possible and boots up userspace with CPU0 offlined. User
1825 can online CPU0 back after boot time.
1827 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1828 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1829 compilation or giving cpu0_hotplug kernel parameter at boot.
1831 If unsure, say N.
1833 config COMPAT_VDSO
1834 def_bool y
1835 prompt "Compat VDSO support"
1836 depends on X86_32 || IA32_EMULATION
1837 ---help---
1838 Map the 32-bit VDSO to the predictable old-style address too.
1840 Say N here if you are running a sufficiently recent glibc
1841 version (2.3.3 or later), to remove the high-mapped
1842 VDSO mapping and to exclusively use the randomized VDSO.
1844 If unsure, say Y.
1846 config CMDLINE_BOOL
1847 bool "Built-in kernel command line"
1848 ---help---
1849 Allow for specifying boot arguments to the kernel at
1850 build time. On some systems (e.g. embedded ones), it is
1851 necessary or convenient to provide some or all of the
1852 kernel boot arguments with the kernel itself (that is,
1853 to not rely on the boot loader to provide them.)
1855 To compile command line arguments into the kernel,
1856 set this option to 'Y', then fill in the
1857 the boot arguments in CONFIG_CMDLINE.
1859 Systems with fully functional boot loaders (i.e. non-embedded)
1860 should leave this option set to 'N'.
1862 config CMDLINE
1863 string "Built-in kernel command string"
1864 depends on CMDLINE_BOOL
1865 default ""
1866 ---help---
1867 Enter arguments here that should be compiled into the kernel
1868 image and used at boot time. If the boot loader provides a
1869 command line at boot time, it is appended to this string to
1870 form the full kernel command line, when the system boots.
1872 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1873 change this behavior.
1875 In most cases, the command line (whether built-in or provided
1876 by the boot loader) should specify the device for the root
1877 file system.
1879 config CMDLINE_OVERRIDE
1880 bool "Built-in command line overrides boot loader arguments"
1881 depends on CMDLINE_BOOL
1882 ---help---
1883 Set this option to 'Y' to have the kernel ignore the boot loader
1884 command line, and use ONLY the built-in command line.
1886 This is used to work around broken boot loaders. This should
1887 be set to 'N' under normal conditions.
1889 endmenu
1891 config ARCH_ENABLE_MEMORY_HOTPLUG
1892 def_bool y
1893 depends on X86_64 || (X86_32 && HIGHMEM)
1895 config ARCH_ENABLE_MEMORY_HOTREMOVE
1896 def_bool y
1897 depends on MEMORY_HOTPLUG
1899 config USE_PERCPU_NUMA_NODE_ID
1900 def_bool y
1901 depends on NUMA
1903 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1904 def_bool y
1905 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1907 menu "Power management and ACPI options"
1909 config ARCH_HIBERNATION_HEADER
1910 def_bool y
1911 depends on X86_64 && HIBERNATION
1913 source "kernel/power/Kconfig"
1915 source "drivers/acpi/Kconfig"
1917 source "drivers/sfi/Kconfig"
1919 config X86_APM_BOOT
1920 def_bool y
1921 depends on APM
1923 menuconfig APM
1924 tristate "APM (Advanced Power Management) BIOS support"
1925 depends on X86_32 && PM_SLEEP
1926 ---help---
1927 APM is a BIOS specification for saving power using several different
1928 techniques. This is mostly useful for battery powered laptops with
1929 APM compliant BIOSes. If you say Y here, the system time will be
1930 reset after a RESUME operation, the /proc/apm device will provide
1931 battery status information, and user-space programs will receive
1932 notification of APM "events" (e.g. battery status change).
1934 If you select "Y" here, you can disable actual use of the APM
1935 BIOS by passing the "apm=off" option to the kernel at boot time.
1937 Note that the APM support is almost completely disabled for
1938 machines with more than one CPU.
1940 In order to use APM, you will need supporting software. For location
1941 and more information, read <file:Documentation/power/apm-acpi.txt>
1942 and the Battery Powered Linux mini-HOWTO, available from
1943 <http://www.tldp.org/docs.html#howto>.
1945 This driver does not spin down disk drives (see the hdparm(8)
1946 manpage ("man 8 hdparm") for that), and it doesn't turn off
1947 VESA-compliant "green" monitors.
1949 This driver does not support the TI 4000M TravelMate and the ACER
1950 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1951 desktop machines also don't have compliant BIOSes, and this driver
1952 may cause those machines to panic during the boot phase.
1954 Generally, if you don't have a battery in your machine, there isn't
1955 much point in using this driver and you should say N. If you get
1956 random kernel OOPSes or reboots that don't seem to be related to
1957 anything, try disabling/enabling this option (or disabling/enabling
1958 APM in your BIOS).
1960 Some other things you should try when experiencing seemingly random,
1961 "weird" problems:
1963 1) make sure that you have enough swap space and that it is
1964 enabled.
1965 2) pass the "no-hlt" option to the kernel
1966 3) switch on floating point emulation in the kernel and pass
1967 the "no387" option to the kernel
1968 4) pass the "floppy=nodma" option to the kernel
1969 5) pass the "mem=4M" option to the kernel (thereby disabling
1970 all but the first 4 MB of RAM)
1971 6) make sure that the CPU is not over clocked.
1972 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1973 8) disable the cache from your BIOS settings
1974 9) install a fan for the video card or exchange video RAM
1975 10) install a better fan for the CPU
1976 11) exchange RAM chips
1977 12) exchange the motherboard.
1979 To compile this driver as a module, choose M here: the
1980 module will be called apm.
1982 if APM
1984 config APM_IGNORE_USER_SUSPEND
1985 bool "Ignore USER SUSPEND"
1986 ---help---
1987 This option will ignore USER SUSPEND requests. On machines with a
1988 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1989 series notebooks, it is necessary to say Y because of a BIOS bug.
1991 config APM_DO_ENABLE
1992 bool "Enable PM at boot time"
1993 ---help---
1994 Enable APM features at boot time. From page 36 of the APM BIOS
1995 specification: "When disabled, the APM BIOS does not automatically
1996 power manage devices, enter the Standby State, enter the Suspend
1997 State, or take power saving steps in response to CPU Idle calls."
1998 This driver will make CPU Idle calls when Linux is idle (unless this
1999 feature is turned off -- see "Do CPU IDLE calls", below). This
2000 should always save battery power, but more complicated APM features
2001 will be dependent on your BIOS implementation. You may need to turn
2002 this option off if your computer hangs at boot time when using APM
2003 support, or if it beeps continuously instead of suspending. Turn
2004 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2005 T400CDT. This is off by default since most machines do fine without
2006 this feature.
2008 config APM_CPU_IDLE
2009 depends on CPU_IDLE
2010 bool "Make CPU Idle calls when idle"
2011 ---help---
2012 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2013 On some machines, this can activate improved power savings, such as
2014 a slowed CPU clock rate, when the machine is idle. These idle calls
2015 are made after the idle loop has run for some length of time (e.g.,
2016 333 mS). On some machines, this will cause a hang at boot time or
2017 whenever the CPU becomes idle. (On machines with more than one CPU,
2018 this option does nothing.)
2020 config APM_DISPLAY_BLANK
2021 bool "Enable console blanking using APM"
2022 ---help---
2023 Enable console blanking using the APM. Some laptops can use this to
2024 turn off the LCD backlight when the screen blanker of the Linux
2025 virtual console blanks the screen. Note that this is only used by
2026 the virtual console screen blanker, and won't turn off the backlight
2027 when using the X Window system. This also doesn't have anything to
2028 do with your VESA-compliant power-saving monitor. Further, this
2029 option doesn't work for all laptops -- it might not turn off your
2030 backlight at all, or it might print a lot of errors to the console,
2031 especially if you are using gpm.
2033 config APM_ALLOW_INTS
2034 bool "Allow interrupts during APM BIOS calls"
2035 ---help---
2036 Normally we disable external interrupts while we are making calls to
2037 the APM BIOS as a measure to lessen the effects of a badly behaving
2038 BIOS implementation. The BIOS should reenable interrupts if it
2039 needs to. Unfortunately, some BIOSes do not -- especially those in
2040 many of the newer IBM Thinkpads. If you experience hangs when you
2041 suspend, try setting this to Y. Otherwise, say N.
2043 endif # APM
2045 source "drivers/cpufreq/Kconfig"
2047 source "drivers/cpuidle/Kconfig"
2049 source "drivers/idle/Kconfig"
2051 endmenu
2054 menu "Bus options (PCI etc.)"
2056 config PCI
2057 bool "PCI support"
2058 default y
2059 ---help---
2060 Find out whether you have a PCI motherboard. PCI is the name of a
2061 bus system, i.e. the way the CPU talks to the other stuff inside
2062 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2063 VESA. If you have PCI, say Y, otherwise N.
2065 choice
2066 prompt "PCI access mode"
2067 depends on X86_32 && PCI
2068 default PCI_GOANY
2069 ---help---
2070 On PCI systems, the BIOS can be used to detect the PCI devices and
2071 determine their configuration. However, some old PCI motherboards
2072 have BIOS bugs and may crash if this is done. Also, some embedded
2073 PCI-based systems don't have any BIOS at all. Linux can also try to
2074 detect the PCI hardware directly without using the BIOS.
2076 With this option, you can specify how Linux should detect the
2077 PCI devices. If you choose "BIOS", the BIOS will be used,
2078 if you choose "Direct", the BIOS won't be used, and if you
2079 choose "MMConfig", then PCI Express MMCONFIG will be used.
2080 If you choose "Any", the kernel will try MMCONFIG, then the
2081 direct access method and falls back to the BIOS if that doesn't
2082 work. If unsure, go with the default, which is "Any".
2084 config PCI_GOBIOS
2085 bool "BIOS"
2087 config PCI_GOMMCONFIG
2088 bool "MMConfig"
2090 config PCI_GODIRECT
2091 bool "Direct"
2093 config PCI_GOOLPC
2094 bool "OLPC XO-1"
2095 depends on OLPC
2097 config PCI_GOANY
2098 bool "Any"
2100 endchoice
2102 config PCI_BIOS
2103 def_bool y
2104 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2106 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2107 config PCI_DIRECT
2108 def_bool y
2109 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2111 config PCI_MMCONFIG
2112 def_bool y
2113 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2115 config PCI_OLPC
2116 def_bool y
2117 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2119 config PCI_XEN
2120 def_bool y
2121 depends on PCI && XEN
2122 select SWIOTLB_XEN
2124 config PCI_DOMAINS
2125 def_bool y
2126 depends on PCI
2128 config PCI_MMCONFIG
2129 bool "Support mmconfig PCI config space access"
2130 depends on X86_64 && PCI && ACPI
2132 config PCI_CNB20LE_QUIRK
2133 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2134 depends on PCI
2135 help
2136 Read the PCI windows out of the CNB20LE host bridge. This allows
2137 PCI hotplug to work on systems with the CNB20LE chipset which do
2138 not have ACPI.
2140 There's no public spec for this chipset, and this functionality
2141 is known to be incomplete.
2143 You should say N unless you know you need this.
2145 source "drivers/pci/pcie/Kconfig"
2147 source "drivers/pci/Kconfig"
2149 # x86_64 have no ISA slots, but can have ISA-style DMA.
2150 config ISA_DMA_API
2151 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2152 default y
2153 help
2154 Enables ISA-style DMA support for devices requiring such controllers.
2155 If unsure, say Y.
2157 if X86_32
2159 config ISA
2160 bool "ISA support"
2161 ---help---
2162 Find out whether you have ISA slots on your motherboard. ISA is the
2163 name of a bus system, i.e. the way the CPU talks to the other stuff
2164 inside your box. Other bus systems are PCI, EISA, MicroChannel
2165 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2166 newer boards don't support it. If you have ISA, say Y, otherwise N.
2168 config EISA
2169 bool "EISA support"
2170 depends on ISA
2171 ---help---
2172 The Extended Industry Standard Architecture (EISA) bus was
2173 developed as an open alternative to the IBM MicroChannel bus.
2175 The EISA bus provided some of the features of the IBM MicroChannel
2176 bus while maintaining backward compatibility with cards made for
2177 the older ISA bus. The EISA bus saw limited use between 1988 and
2178 1995 when it was made obsolete by the PCI bus.
2180 Say Y here if you are building a kernel for an EISA-based machine.
2182 Otherwise, say N.
2184 source "drivers/eisa/Kconfig"
2186 config SCx200
2187 tristate "NatSemi SCx200 support"
2188 ---help---
2189 This provides basic support for National Semiconductor's
2190 (now AMD's) Geode processors. The driver probes for the
2191 PCI-IDs of several on-chip devices, so its a good dependency
2192 for other scx200_* drivers.
2194 If compiled as a module, the driver is named scx200.
2196 config SCx200HR_TIMER
2197 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2198 depends on SCx200
2199 default y
2200 ---help---
2201 This driver provides a clocksource built upon the on-chip
2202 27MHz high-resolution timer. Its also a workaround for
2203 NSC Geode SC-1100's buggy TSC, which loses time when the
2204 processor goes idle (as is done by the scheduler). The
2205 other workaround is idle=poll boot option.
2207 config OLPC
2208 bool "One Laptop Per Child support"
2209 depends on !X86_PAE
2210 select GPIOLIB
2211 select OF
2212 select OF_PROMTREE
2213 select IRQ_DOMAIN
2214 ---help---
2215 Add support for detecting the unique features of the OLPC
2216 XO hardware.
2218 config OLPC_XO1_PM
2219 bool "OLPC XO-1 Power Management"
2220 depends on OLPC && MFD_CS5535 && PM_SLEEP
2221 select MFD_CORE
2222 ---help---
2223 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2225 config OLPC_XO1_RTC
2226 bool "OLPC XO-1 Real Time Clock"
2227 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2228 ---help---
2229 Add support for the XO-1 real time clock, which can be used as a
2230 programmable wakeup source.
2232 config OLPC_XO1_SCI
2233 bool "OLPC XO-1 SCI extras"
2234 depends on OLPC && OLPC_XO1_PM
2235 depends on INPUT=y
2236 select POWER_SUPPLY
2237 select GPIO_CS5535
2238 select MFD_CORE
2239 ---help---
2240 Add support for SCI-based features of the OLPC XO-1 laptop:
2241 - EC-driven system wakeups
2242 - Power button
2243 - Ebook switch
2244 - Lid switch
2245 - AC adapter status updates
2246 - Battery status updates
2248 config OLPC_XO15_SCI
2249 bool "OLPC XO-1.5 SCI extras"
2250 depends on OLPC && ACPI
2251 select POWER_SUPPLY
2252 ---help---
2253 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2254 - EC-driven system wakeups
2255 - AC adapter status updates
2256 - Battery status updates
2258 config ALIX
2259 bool "PCEngines ALIX System Support (LED setup)"
2260 select GPIOLIB
2261 ---help---
2262 This option enables system support for the PCEngines ALIX.
2263 At present this just sets up LEDs for GPIO control on
2264 ALIX2/3/6 boards. However, other system specific setup should
2265 get added here.
2267 Note: You must still enable the drivers for GPIO and LED support
2268 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2270 Note: You have to set alix.force=1 for boards with Award BIOS.
2272 config NET5501
2273 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2274 select GPIOLIB
2275 ---help---
2276 This option enables system support for the Soekris Engineering net5501.
2278 config GEOS
2279 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2280 select GPIOLIB
2281 depends on DMI
2282 ---help---
2283 This option enables system support for the Traverse Technologies GEOS.
2285 config TS5500
2286 bool "Technologic Systems TS-5500 platform support"
2287 depends on MELAN
2288 select CHECK_SIGNATURE
2289 select NEW_LEDS
2290 select LEDS_CLASS
2291 ---help---
2292 This option enables system support for the Technologic Systems TS-5500.
2294 endif # X86_32
2296 config AMD_NB
2297 def_bool y
2298 depends on CPU_SUP_AMD && PCI
2300 source "drivers/pcmcia/Kconfig"
2302 source "drivers/pci/hotplug/Kconfig"
2304 config RAPIDIO
2305 tristate "RapidIO support"
2306 depends on PCI
2307 default n
2308 help
2309 If enabled this option will include drivers and the core
2310 infrastructure code to support RapidIO interconnect devices.
2312 source "drivers/rapidio/Kconfig"
2314 config X86_SYSFB
2315 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2316 help
2317 Firmwares often provide initial graphics framebuffers so the BIOS,
2318 bootloader or kernel can show basic video-output during boot for
2319 user-guidance and debugging. Historically, x86 used the VESA BIOS
2320 Extensions and EFI-framebuffers for this, which are mostly limited
2321 to x86.
2322 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2323 framebuffers so the new generic system-framebuffer drivers can be
2324 used on x86. If the framebuffer is not compatible with the generic
2325 modes, it is adverticed as fallback platform framebuffer so legacy
2326 drivers like efifb, vesafb and uvesafb can pick it up.
2327 If this option is not selected, all system framebuffers are always
2328 marked as fallback platform framebuffers as usual.
2330 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2331 not be able to pick up generic system framebuffers if this option
2332 is selected. You are highly encouraged to enable simplefb as
2333 replacement if you select this option. simplefb can correctly deal
2334 with generic system framebuffers. But you should still keep vesafb
2335 and others enabled as fallback if a system framebuffer is
2336 incompatible with simplefb.
2338 If unsure, say Y.
2340 endmenu
2343 menu "Executable file formats / Emulations"
2345 source "fs/Kconfig.binfmt"
2347 config IA32_EMULATION
2348 bool "IA32 Emulation"
2349 depends on X86_64
2350 select BINFMT_ELF
2351 select COMPAT_BINFMT_ELF
2352 select HAVE_UID16
2353 ---help---
2354 Include code to run legacy 32-bit programs under a
2355 64-bit kernel. You should likely turn this on, unless you're
2356 100% sure that you don't have any 32-bit programs left.
2358 config IA32_AOUT
2359 tristate "IA32 a.out support"
2360 depends on IA32_EMULATION
2361 ---help---
2362 Support old a.out binaries in the 32bit emulation.
2364 config X86_X32
2365 bool "x32 ABI for 64-bit mode"
2366 depends on X86_64 && IA32_EMULATION
2367 ---help---
2368 Include code to run binaries for the x32 native 32-bit ABI
2369 for 64-bit processors. An x32 process gets access to the
2370 full 64-bit register file and wide data path while leaving
2371 pointers at 32 bits for smaller memory footprint.
2373 You will need a recent binutils (2.22 or later) with
2374 elf32_x86_64 support enabled to compile a kernel with this
2375 option set.
2377 config COMPAT
2378 def_bool y
2379 depends on IA32_EMULATION || X86_X32
2380 select ARCH_WANT_OLD_COMPAT_IPC
2382 if COMPAT
2383 config COMPAT_FOR_U64_ALIGNMENT
2384 def_bool y
2386 config SYSVIPC_COMPAT
2387 def_bool y
2388 depends on SYSVIPC
2390 config KEYS_COMPAT
2391 def_bool y
2392 depends on KEYS
2393 endif
2395 endmenu
2398 config HAVE_ATOMIC_IOMAP
2399 def_bool y
2400 depends on X86_32
2402 config X86_DEV_DMA_OPS
2403 bool
2404 depends on X86_64 || STA2X11
2406 config X86_DMA_REMAP
2407 bool
2408 depends on STA2X11
2410 source "net/Kconfig"
2412 source "drivers/Kconfig"
2414 source "drivers/firmware/Kconfig"
2416 source "fs/Kconfig"
2418 source "arch/x86/Kconfig.debug"
2420 source "security/Kconfig"
2422 source "crypto/Kconfig"
2424 source "arch/x86/kvm/Kconfig"
2426 source "lib/Kconfig"