| blob | fcefdda5136dde37c2a8893519912286f6551cf5 |
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 if X86_64
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
45 select HAVE_KRETPROBES
46 select GENERIC_EARLY_IOREMAP
47 select HAVE_OPTPROBES
48 select HAVE_KPROBES_ON_FTRACE
49 select HAVE_FTRACE_MCOUNT_RECORD
50 select HAVE_FENTRY if X86_64
51 select HAVE_C_RECORDMCOUNT
52 select HAVE_DYNAMIC_FTRACE
53 select HAVE_DYNAMIC_FTRACE_WITH_REGS
54 select HAVE_FUNCTION_TRACER
55 select HAVE_FUNCTION_GRAPH_TRACER
56 select HAVE_FUNCTION_GRAPH_FP_TEST
57 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
58 select HAVE_SYSCALL_TRACEPOINTS
59 select SYSCTL_EXCEPTION_TRACE
60 select HAVE_KVM
61 select HAVE_ARCH_KGDB
62 select HAVE_ARCH_TRACEHOOK
63 select HAVE_GENERIC_DMA_COHERENT if X86_32
64 select HAVE_EFFICIENT_UNALIGNED_ACCESS
65 select USER_STACKTRACE_SUPPORT
66 select HAVE_REGS_AND_STACK_ACCESS_API
67 select HAVE_DMA_API_DEBUG
68 select HAVE_KERNEL_GZIP
69 select HAVE_KERNEL_BZIP2
70 select HAVE_KERNEL_LZMA
71 select HAVE_KERNEL_XZ
72 select HAVE_KERNEL_LZO
73 select HAVE_KERNEL_LZ4
74 select HAVE_HW_BREAKPOINT
75 select HAVE_MIXED_BREAKPOINTS_REGS
76 select PERF_EVENTS
77 select HAVE_PERF_EVENTS_NMI
78 select HAVE_PERF_REGS
79 select HAVE_PERF_USER_STACK_DUMP
80 select HAVE_DEBUG_KMEMLEAK
81 select ANON_INODES
82 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
83 select HAVE_CMPXCHG_LOCAL
84 select HAVE_CMPXCHG_DOUBLE
85 select HAVE_ARCH_KMEMCHECK
86 select HAVE_USER_RETURN_NOTIFIER
87 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
88 select HAVE_ARCH_JUMP_LABEL
89 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90 select SPARSE_IRQ
91 select GENERIC_FIND_FIRST_BIT
92 select GENERIC_IRQ_PROBE
93 select GENERIC_PENDING_IRQ if SMP
94 select GENERIC_IRQ_SHOW
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select IRQ_FORCED_THREADING
97 select HAVE_BPF_JIT if X86_64
98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select CLKEVT_I8253
100 select ARCH_HAVE_NMI_SAFE_CMPXCHG
101 select GENERIC_IOMAP
102 select DCACHE_WORD_ACCESS
103 select GENERIC_SMP_IDLE_THREAD
104 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
105 select HAVE_ARCH_SECCOMP_FILTER
106 select BUILDTIME_EXTABLE_SORT
107 select GENERIC_CMOS_UPDATE
108 select HAVE_ARCH_SOFT_DIRTY if X86_64
109 select CLOCKSOURCE_WATCHDOG
110 select GENERIC_CLOCKEVENTS
111 select ARCH_CLOCKSOURCE_DATA
112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113 select GENERIC_TIME_VSYSCALL
114 select KTIME_SCALAR if X86_32
115 select GENERIC_STRNCPY_FROM_USER
116 select GENERIC_STRNLEN_USER
117 select HAVE_CONTEXT_TRACKING if X86_64
118 select HAVE_IRQ_TIME_ACCOUNTING
119 select VIRT_TO_BUS
120 select MODULES_USE_ELF_REL if X86_32
121 select MODULES_USE_ELF_RELA if X86_64
122 select CLONE_BACKWARDS if X86_32
123 select ARCH_USE_BUILTIN_BSWAP
124 select ARCH_USE_QUEUE_RWLOCK
125 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
126 select OLD_SIGACTION if X86_32
127 select COMPAT_OLD_SIGACTION if IA32_EMULATION
128 select RTC_LIB
129 select HAVE_DEBUG_STACKOVERFLOW
130 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
131 select HAVE_CC_STACKPROTECTOR
132 select GENERIC_CPU_AUTOPROBE
133 select HAVE_ARCH_AUDITSYSCALL
135 config INSTRUCTION_DECODER
136 def_bool y
137 depends on KPROBES || PERF_EVENTS || UPROBES
139 config OUTPUT_FORMAT
140 string
141 default "elf32-i386" if X86_32
142 default "elf64-x86-64" if X86_64
144 config ARCH_DEFCONFIG
145 string
146 default "arch/x86/configs/i386_defconfig" if X86_32
147 default "arch/x86/configs/x86_64_defconfig" if X86_64
149 config LOCKDEP_SUPPORT
150 def_bool y
152 config STACKTRACE_SUPPORT
153 def_bool y
155 config HAVE_LATENCYTOP_SUPPORT
156 def_bool y
158 config MMU
159 def_bool y
161 config SBUS
162 bool
164 config NEED_DMA_MAP_STATE
165 def_bool y
166 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
168 config NEED_SG_DMA_LENGTH
169 def_bool y
171 config GENERIC_ISA_DMA
172 def_bool y
173 depends on ISA_DMA_API
175 config GENERIC_BUG
176 def_bool y
177 depends on BUG
178 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
180 config GENERIC_BUG_RELATIVE_POINTERS
181 bool
183 config GENERIC_HWEIGHT
184 def_bool y
186 config ARCH_MAY_HAVE_PC_FDC
187 def_bool y
188 depends on ISA_DMA_API
190 config RWSEM_XCHGADD_ALGORITHM
191 def_bool y
193 config GENERIC_CALIBRATE_DELAY
194 def_bool y
196 config ARCH_HAS_CPU_RELAX
197 def_bool y
199 config ARCH_HAS_CACHE_LINE_SIZE
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 config FIX_EARLYCON_MEM
266 def_bool y
268 source "init/Kconfig"
269 source "kernel/Kconfig.freezer"
271 menu "Processor type and features"
273 config ZONE_DMA
274 bool "DMA memory allocation support" if EXPERT
275 default y
276 help
277 DMA memory allocation support allows devices with less than 32-bit
278 addressing to allocate within the first 16MB of address space.
279 Disable if no such devices will be used.
281 If unsure, say Y.
283 config SMP
284 bool "Symmetric multi-processing support"
285 ---help---
286 This enables support for systems with more than one CPU. If you have
287 a system with only one CPU, say N. If you have a system with more
288 than one CPU, say Y.
290 If you say N here, the kernel will run on uni- and multiprocessor
291 machines, but will use only one CPU of a multiprocessor machine. If
292 you say Y here, the kernel will run on many, but not all,
293 uniprocessor machines. On a uniprocessor machine, the kernel
294 will run faster if you say N here.
296 Note that if you say Y here and choose architecture "586" or
297 "Pentium" under "Processor family", the kernel will not work on 486
298 architectures. Similarly, multiprocessor kernels for the "PPro"
299 architecture may not work on all Pentium based boards.
301 People using multiprocessor machines who say Y here should also say
302 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
303 Management" code will be disabled if you say Y here.
305 See also <file:Documentation/x86/i386/IO-APIC.txt>,
306 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
307 <http://www.tldp.org/docs.html#howto>.
309 If you don't know what to do here, say N.
311 config X86_X2APIC
312 bool "Support x2apic"
313 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
314 ---help---
315 This enables x2apic support on CPUs that have this feature.
317 This allows 32-bit apic IDs (so it can support very large systems),
318 and accesses the local apic via MSRs not via mmio.
320 If you don't know what to do here, say N.
322 config X86_MPPARSE
323 bool "Enable MPS table" if ACPI || SFI
324 default y
325 depends on X86_LOCAL_APIC
326 ---help---
327 For old smp systems that do not have proper acpi support. Newer systems
328 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
330 config X86_BIGSMP
331 bool "Support for big SMP systems with more than 8 CPUs"
332 depends on X86_32 && SMP
333 ---help---
334 This option is needed for the systems that have more than 8 CPUs
336 config GOLDFISH
337 def_bool y
338 depends on X86_GOLDFISH
340 if X86_32
341 config X86_EXTENDED_PLATFORM
342 bool "Support for extended (non-PC) x86 platforms"
343 default y
344 ---help---
345 If you disable this option then the kernel will only support
346 standard PC platforms. (which covers the vast majority of
347 systems out there.)
349 If you enable this option then you'll be able to select support
350 for the following (non-PC) 32 bit x86 platforms:
351 Goldfish (Android emulator)
352 AMD Elan
353 RDC R-321x SoC
354 SGI 320/540 (Visual Workstation)
355 STA2X11-based (e.g. Northville)
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_EXTENDED_PLATFORM
423 ---help---
424 Enable support for the Goldfish virtual platform used primarily
425 for Android development. Unless you are building for the Android
426 Goldfish emulator say N here.
428 config X86_INTEL_CE
429 bool "CE4100 TV platform"
430 depends on PCI
431 depends on PCI_GODIRECT
432 depends on X86_32
433 depends on X86_EXTENDED_PLATFORM
434 select X86_REBOOTFIXUPS
435 select OF
436 select OF_EARLY_FLATTREE
437 select IRQ_DOMAIN
438 ---help---
439 Select for the Intel CE media processor (CE4100) SOC.
440 This option compiles in support for the CE4100 SOC for settop
441 boxes and media devices.
443 config X86_INTEL_MID
444 bool "Intel MID platform support"
445 depends on X86_32
446 depends on X86_EXTENDED_PLATFORM
447 depends on X86_PLATFORM_DEVICES
448 depends on PCI
449 depends on PCI_GOANY
450 depends on X86_IO_APIC
451 select SFI
452 select I2C
453 select DW_APB_TIMER
454 select APB_TIMER
455 select INTEL_SCU_IPC
456 select MFD_INTEL_MSIC
457 ---help---
458 Select to build a kernel capable of supporting Intel MID (Mobile
459 Internet Device) platform systems which do not have the PCI legacy
460 interfaces. If you are building for a PC class system say N here.
462 Intel MID platforms are based on an Intel processor and chipset which
463 consume less power than most of the x86 derivatives.
465 config X86_INTEL_LPSS
466 bool "Intel Low Power Subsystem Support"
467 depends on ACPI
468 select COMMON_CLK
469 select PINCTRL
470 ---help---
471 Select to build support for Intel Low Power Subsystem such as
472 found on Intel Lynxpoint PCH. Selecting this option enables
473 things like clock tree (common clock framework) and pincontrol
474 which are needed by the LPSS peripheral drivers.
476 config X86_RDC321X
477 bool "RDC R-321x SoC"
478 depends on X86_32
479 depends on X86_EXTENDED_PLATFORM
480 select M486
481 select X86_REBOOTFIXUPS
482 ---help---
483 This option is needed for RDC R-321x system-on-chip, also known
484 as R-8610-(G).
485 If you don't have one of these chips, you should say N here.
487 config X86_32_NON_STANDARD
488 bool "Support non-standard 32-bit SMP architectures"
489 depends on X86_32 && SMP
490 depends on X86_EXTENDED_PLATFORM
491 ---help---
492 This option compiles in the bigsmp and STA2X11 default
493 subarchitectures. It is intended for a generic binary
494 kernel. If you select them all, kernel will probe it one by
495 one and will fallback to default.
497 # Alphabetically sorted list of Non standard 32 bit platforms
499 config X86_SUPPORTS_MEMORY_FAILURE
500 def_bool y
501 # MCE code calls memory_failure():
502 depends on X86_MCE
503 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
504 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
505 depends on X86_64 || !SPARSEMEM
506 select ARCH_SUPPORTS_MEMORY_FAILURE
508 config STA2X11
509 bool "STA2X11 Companion Chip Support"
510 depends on X86_32_NON_STANDARD && PCI
511 select X86_DEV_DMA_OPS
512 select X86_DMA_REMAP
513 select SWIOTLB
514 select MFD_STA2X11
515 select ARCH_REQUIRE_GPIOLIB
516 default n
517 ---help---
518 This adds support for boards based on the STA2X11 IO-Hub,
519 a.k.a. "ConneXt". The chip is used in place of the standard
520 PC chipset, so all "standard" peripherals are missing. If this
521 option is selected the kernel will still be able to boot on
522 standard PC machines.
524 config X86_32_IRIS
525 tristate "Eurobraille/Iris poweroff module"
526 depends on X86_32
527 ---help---
528 The Iris machines from EuroBraille do not have APM or ACPI support
529 to shut themselves down properly. A special I/O sequence is
530 needed to do so, which is what this module does at
531 kernel shutdown.
533 This is only for Iris machines from EuroBraille.
535 If unused, say N.
537 config SCHED_OMIT_FRAME_POINTER
538 def_bool y
539 prompt "Single-depth WCHAN output"
540 depends on X86
541 ---help---
542 Calculate simpler /proc/<PID>/wchan values. If this option
543 is disabled then wchan values will recurse back to the
544 caller function. This provides more accurate wchan values,
545 at the expense of slightly more scheduling overhead.
547 If in doubt, say "Y".
549 menuconfig HYPERVISOR_GUEST
550 bool "Linux guest support"
551 ---help---
552 Say Y here to enable options for running Linux under various hyper-
553 visors. This option enables basic hypervisor detection and platform
554 setup.
556 If you say N, all options in this submenu will be skipped and
557 disabled, and Linux guest support won't be built in.
559 if HYPERVISOR_GUEST
561 config PARAVIRT
562 bool "Enable paravirtualization code"
563 ---help---
564 This changes the kernel so it can modify itself when it is run
565 under a hypervisor, potentially improving performance significantly
566 over full virtualization. However, when run without a hypervisor
567 the kernel is theoretically slower and slightly larger.
569 config PARAVIRT_DEBUG
570 bool "paravirt-ops debugging"
571 depends on PARAVIRT && DEBUG_KERNEL
572 ---help---
573 Enable to debug paravirt_ops internals. Specifically, BUG if
574 a paravirt_op is missing when it is called.
576 config PARAVIRT_SPINLOCKS
577 bool "Paravirtualization layer for spinlocks"
578 depends on PARAVIRT && SMP
579 select UNINLINE_SPIN_UNLOCK
580 ---help---
581 Paravirtualized spinlocks allow a pvops backend to replace the
582 spinlock implementation with something virtualization-friendly
583 (for example, block the virtual CPU rather than spinning).
585 It has a minimal impact on native kernels and gives a nice performance
586 benefit on paravirtualized KVM / Xen kernels.
588 If you are unsure how to answer this question, answer Y.
590 source "arch/x86/xen/Kconfig"
592 config KVM_GUEST
593 bool "KVM Guest support (including kvmclock)"
594 depends on PARAVIRT
595 select PARAVIRT_CLOCK
596 default y
597 ---help---
598 This option enables various optimizations for running under the KVM
599 hypervisor. It includes a paravirtualized clock, so that instead
600 of relying on a PIT (or probably other) emulation by the
601 underlying device model, the host provides the guest with
602 timing infrastructure such as time of day, and system time
604 config KVM_DEBUG_FS
605 bool "Enable debug information for KVM Guests in debugfs"
606 depends on KVM_GUEST && DEBUG_FS
607 default n
608 ---help---
609 This option enables collection of various statistics for KVM guest.
610 Statistics are displayed in debugfs filesystem. Enabling this option
611 may incur significant overhead.
613 source "arch/x86/lguest/Kconfig"
615 config PARAVIRT_TIME_ACCOUNTING
616 bool "Paravirtual steal time accounting"
617 depends on PARAVIRT
618 default n
619 ---help---
620 Select this option to enable fine granularity task steal time
621 accounting. Time spent executing other tasks in parallel with
622 the current vCPU is discounted from the vCPU power. To account for
623 that, there can be a small performance impact.
625 If in doubt, say N here.
627 config PARAVIRT_CLOCK
628 bool
630 endif #HYPERVISOR_GUEST
632 config NO_BOOTMEM
633 def_bool y
635 config MEMTEST
636 bool "Memtest"
637 ---help---
638 This option adds a kernel parameter 'memtest', which allows memtest
639 to be set.
640 memtest=0, mean disabled; -- default
641 memtest=1, mean do 1 test pattern;
642 ...
643 memtest=4, mean do 4 test patterns.
644 If you are unsure how to answer this question, answer N.
646 source "arch/x86/Kconfig.cpu"
648 config HPET_TIMER
649 def_bool X86_64
650 prompt "HPET Timer Support" if X86_32
651 ---help---
652 Use the IA-PC HPET (High Precision Event Timer) to manage
653 time in preference to the PIT and RTC, if a HPET is
654 present.
655 HPET is the next generation timer replacing legacy 8254s.
656 The HPET provides a stable time base on SMP
657 systems, unlike the TSC, but it is more expensive to access,
658 as it is off-chip. You can find the HPET spec at
659 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
661 You can safely choose Y here. However, HPET will only be
662 activated if the platform and the BIOS support this feature.
663 Otherwise the 8254 will be used for timing services.
665 Choose N to continue using the legacy 8254 timer.
667 config HPET_EMULATE_RTC
668 def_bool y
669 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
671 config APB_TIMER
672 def_bool y if X86_INTEL_MID
673 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
674 select DW_APB_TIMER
675 depends on X86_INTEL_MID && SFI
676 help
677 APB timer is the replacement for 8254, HPET on X86 MID platforms.
678 The APBT provides a stable time base on SMP
679 systems, unlike the TSC, but it is more expensive to access,
680 as it is off-chip. APB timers are always running regardless of CPU
681 C states, they are used as per CPU clockevent device when possible.
683 # Mark as expert because too many people got it wrong.
684 # The code disables itself when not needed.
685 config DMI
686 default y
687 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
688 bool "Enable DMI scanning" if EXPERT
689 ---help---
690 Enabled scanning of DMI to identify machine quirks. Say Y
691 here unless you have verified that your setup is not
692 affected by entries in the DMI blacklist. Required by PNP
693 BIOS code.
695 config GART_IOMMU
696 bool "Old AMD GART IOMMU support"
697 select SWIOTLB
698 depends on X86_64 && PCI && AMD_NB
699 ---help---
700 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
701 GART based hardware IOMMUs.
703 The GART supports full DMA access for devices with 32-bit access
704 limitations, on systems with more than 3 GB. This is usually needed
705 for USB, sound, many IDE/SATA chipsets and some other devices.
707 Newer systems typically have a modern AMD IOMMU, supported via
708 the CONFIG_AMD_IOMMU=y config option.
710 In normal configurations this driver is only active when needed:
711 there's more than 3 GB of memory and the system contains a
712 32-bit limited device.
714 If unsure, say Y.
716 config CALGARY_IOMMU
717 bool "IBM Calgary IOMMU support"
718 select SWIOTLB
719 depends on X86_64 && PCI
720 ---help---
721 Support for hardware IOMMUs in IBM's xSeries x366 and x460
722 systems. Needed to run systems with more than 3GB of memory
723 properly with 32-bit PCI devices that do not support DAC
724 (Double Address Cycle). Calgary also supports bus level
725 isolation, where all DMAs pass through the IOMMU. This
726 prevents them from going anywhere except their intended
727 destination. This catches hard-to-find kernel bugs and
728 mis-behaving drivers and devices that do not use the DMA-API
729 properly to set up their DMA buffers. The IOMMU can be
730 turned off at boot time with the iommu=off parameter.
731 Normally the kernel will make the right choice by itself.
732 If unsure, say Y.
734 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
735 def_bool y
736 prompt "Should Calgary be enabled by default?"
737 depends on CALGARY_IOMMU
738 ---help---
739 Should Calgary be enabled by default? if you choose 'y', Calgary
740 will be used (if it exists). If you choose 'n', Calgary will not be
741 used even if it exists. If you choose 'n' and would like to use
742 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
743 If unsure, say Y.
745 # need this always selected by IOMMU for the VIA workaround
746 config SWIOTLB
747 def_bool y if X86_64
748 ---help---
749 Support for software bounce buffers used on x86-64 systems
750 which don't have a hardware IOMMU. Using this PCI devices
751 which can only access 32-bits of memory can be used on systems
752 with more than 3 GB of memory.
753 If unsure, say Y.
755 config IOMMU_HELPER
756 def_bool y
757 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
759 config MAXSMP
760 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
761 depends on X86_64 && SMP && DEBUG_KERNEL
762 select CPUMASK_OFFSTACK
763 ---help---
764 Enable maximum number of CPUS and NUMA Nodes for this architecture.
765 If unsure, say N.
767 config NR_CPUS
768 int "Maximum number of CPUs" if SMP && !MAXSMP
769 range 2 8 if SMP && X86_32 && !X86_BIGSMP
770 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
771 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
772 default "1" if !SMP
773 default "8192" if MAXSMP
774 default "32" if SMP && X86_BIGSMP
775 default "8" if SMP
776 ---help---
777 This allows you to specify the maximum number of CPUs which this
778 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
779 supported value is 4096, otherwise the maximum value is 512. The
780 minimum value which makes sense is 2.
782 This is purely to save memory - each supported CPU adds
783 approximately eight kilobytes to the kernel image.
785 config SCHED_SMT
786 bool "SMT (Hyperthreading) scheduler support"
787 depends on X86_HT
788 ---help---
789 SMT scheduler support improves the CPU scheduler's decision making
790 when dealing with Intel Pentium 4 chips with HyperThreading at a
791 cost of slightly increased overhead in some places. If unsure say
792 N here.
794 config SCHED_MC
795 def_bool y
796 prompt "Multi-core scheduler support"
797 depends on X86_HT
798 ---help---
799 Multi-core scheduler support improves the CPU scheduler's decision
800 making when dealing with multi-core CPU chips at a cost of slightly
801 increased overhead in some places. If unsure say N here.
803 source "kernel/Kconfig.preempt"
805 config X86_UP_APIC
806 bool "Local APIC support on uniprocessors"
807 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
808 ---help---
809 A local APIC (Advanced Programmable Interrupt Controller) is an
810 integrated interrupt controller in the CPU. If you have a single-CPU
811 system which has a processor with a local APIC, you can say Y here to
812 enable and use it. If you say Y here even though your machine doesn't
813 have a local APIC, then the kernel will still run with no slowdown at
814 all. The local APIC supports CPU-generated self-interrupts (timer,
815 performance counters), and the NMI watchdog which detects hard
816 lockups.
818 config X86_UP_IOAPIC
819 bool "IO-APIC support on uniprocessors"
820 depends on X86_UP_APIC
821 ---help---
822 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
823 SMP-capable replacement for PC-style interrupt controllers. Most
824 SMP systems and many recent uniprocessor systems have one.
826 If you have a single-CPU system with an IO-APIC, you can say Y here
827 to use it. If you say Y here even though your machine doesn't have
828 an IO-APIC, then the kernel will still run with no slowdown at all.
830 config X86_LOCAL_APIC
831 def_bool y
832 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
834 config X86_IO_APIC
835 def_bool y
836 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
837 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
839 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
840 bool "Reroute for broken boot IRQs"
841 depends on X86_IO_APIC
842 ---help---
843 This option enables a workaround that fixes a source of
844 spurious interrupts. This is recommended when threaded
845 interrupt handling is used on systems where the generation of
846 superfluous "boot interrupts" cannot be disabled.
848 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
849 entry in the chipset's IO-APIC is masked (as, e.g. the RT
850 kernel does during interrupt handling). On chipsets where this
851 boot IRQ generation cannot be disabled, this workaround keeps
852 the original IRQ line masked so that only the equivalent "boot
853 IRQ" is delivered to the CPUs. The workaround also tells the
854 kernel to set up the IRQ handler on the boot IRQ line. In this
855 way only one interrupt is delivered to the kernel. Otherwise
856 the spurious second interrupt may cause the kernel to bring
857 down (vital) interrupt lines.
859 Only affects "broken" chipsets. Interrupt sharing may be
860 increased on these systems.
862 config X86_MCE
863 bool "Machine Check / overheating reporting"
864 default y
865 ---help---
866 Machine Check support allows the processor to notify the
867 kernel if it detects a problem (e.g. overheating, data corruption).
868 The action the kernel takes depends on the severity of the problem,
869 ranging from warning messages to halting the machine.
871 config X86_MCE_INTEL
872 def_bool y
873 prompt "Intel MCE features"
874 depends on X86_MCE && X86_LOCAL_APIC
875 ---help---
876 Additional support for intel specific MCE features such as
877 the thermal monitor.
879 config X86_MCE_AMD
880 def_bool y
881 prompt "AMD MCE features"
882 depends on X86_MCE && X86_LOCAL_APIC
883 ---help---
884 Additional support for AMD specific MCE features such as
885 the DRAM Error Threshold.
887 config X86_ANCIENT_MCE
888 bool "Support for old Pentium 5 / WinChip machine checks"
889 depends on X86_32 && X86_MCE
890 ---help---
891 Include support for machine check handling on old Pentium 5 or WinChip
892 systems. These typically need to be enabled explicitly on the command
893 line.
895 config X86_MCE_THRESHOLD
896 depends on X86_MCE_AMD || X86_MCE_INTEL
897 def_bool y
899 config X86_MCE_INJECT
900 depends on X86_MCE
901 tristate "Machine check injector support"
902 ---help---
903 Provide support for injecting machine checks for testing purposes.
904 If you don't know what a machine check is and you don't do kernel
905 QA it is safe to say n.
907 config X86_THERMAL_VECTOR
908 def_bool y
909 depends on X86_MCE_INTEL
911 config VM86
912 bool "Enable VM86 support" if EXPERT
913 default y
914 depends on X86_32
915 ---help---
916 This option is required by programs like DOSEMU to run
917 16-bit real mode legacy code on x86 processors. It also may
918 be needed by software like XFree86 to initialize some video
919 cards via BIOS. Disabling this option saves about 6K.
921 config X86_16BIT
922 bool "Enable support for 16-bit segments" if EXPERT
923 default y
924 ---help---
925 This option is required by programs like Wine to run 16-bit
926 protected mode legacy code on x86 processors. Disabling
927 this option saves about 300 bytes on i386, or around 6K text
928 plus 16K runtime memory on x86-64,
930 config X86_ESPFIX32
931 def_bool y
932 depends on X86_16BIT && X86_32
934 config X86_ESPFIX64
935 def_bool y
936 depends on X86_16BIT && X86_64
938 config TOSHIBA
939 tristate "Toshiba Laptop support"
940 depends on X86_32
941 ---help---
942 This adds a driver to safely access the System Management Mode of
943 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
944 not work on models with a Phoenix BIOS. The System Management Mode
945 is used to set the BIOS and power saving options on Toshiba portables.
947 For information on utilities to make use of this driver see the
948 Toshiba Linux utilities web site at:
949 <http://www.buzzard.org.uk/toshiba/>.
951 Say Y if you intend to run this kernel on a Toshiba portable.
952 Say N otherwise.
954 config I8K
955 tristate "Dell laptop support"
956 select HWMON
957 ---help---
958 This adds a driver to safely access the System Management Mode
959 of the CPU on the Dell Inspiron 8000. The System Management Mode
960 is used to read cpu temperature and cooling fan status and to
961 control the fans on the I8K portables.
963 This driver has been tested only on the Inspiron 8000 but it may
964 also work with other Dell laptops. You can force loading on other
965 models by passing the parameter `force=1' to the module. Use at
966 your own risk.
968 For information on utilities to make use of this driver see the
969 I8K Linux utilities web site at:
970 <http://people.debian.org/~dz/i8k/>
972 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
973 Say N otherwise.
975 config X86_REBOOTFIXUPS
976 bool "Enable X86 board specific fixups for reboot"
977 depends on X86_32
978 ---help---
979 This enables chipset and/or board specific fixups to be done
980 in order to get reboot to work correctly. This is only needed on
981 some combinations of hardware and BIOS. The symptom, for which
982 this config is intended, is when reboot ends with a stalled/hung
983 system.
985 Currently, the only fixup is for the Geode machines using
986 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
988 Say Y if you want to enable the fixup. Currently, it's safe to
989 enable this option even if you don't need it.
990 Say N otherwise.
992 config MICROCODE
993 tristate "CPU microcode loading support"
994 depends on CPU_SUP_AMD || CPU_SUP_INTEL
995 select FW_LOADER
996 ---help---
998 If you say Y here, you will be able to update the microcode on
999 certain Intel and AMD processors. The Intel support is for the
1000 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1001 Xeon etc. The AMD support is for families 0x10 and later. You will
1002 obviously need the actual microcode binary data itself which is not
1003 shipped with the Linux kernel.
1005 This option selects the general module only, you need to select
1006 at least one vendor specific module as well.
1008 To compile this driver as a module, choose M here: the module
1009 will be called microcode.
1011 config MICROCODE_INTEL
1012 bool "Intel microcode loading support"
1013 depends on MICROCODE
1014 default MICROCODE
1015 select FW_LOADER
1016 ---help---
1017 This options enables microcode patch loading support for Intel
1018 processors.
1020 For the current Intel microcode data package go to
1021 <https://downloadcenter.intel.com> and search for
1022 'Linux Processor Microcode Data File'.
1024 config MICROCODE_AMD
1025 bool "AMD microcode loading support"
1026 depends on MICROCODE
1027 select FW_LOADER
1028 ---help---
1029 If you select this option, microcode patch loading support for AMD
1030 processors will be enabled.
1032 config MICROCODE_OLD_INTERFACE
1033 def_bool y
1034 depends on MICROCODE
1036 config MICROCODE_INTEL_EARLY
1037 def_bool n
1039 config MICROCODE_AMD_EARLY
1040 def_bool n
1042 config MICROCODE_EARLY
1043 bool "Early load microcode"
1044 depends on MICROCODE=y && BLK_DEV_INITRD
1045 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1046 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1047 default y
1048 help
1049 This option provides functionality to read additional microcode data
1050 at the beginning of initrd image. The data tells kernel to load
1051 microcode to CPU's as early as possible. No functional change if no
1052 microcode data is glued to the initrd, therefore it's safe to say Y.
1054 config X86_MSR
1055 tristate "/dev/cpu/*/msr - Model-specific register support"
1056 ---help---
1057 This device gives privileged processes access to the x86
1058 Model-Specific Registers (MSRs). It is a character device with
1059 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1060 MSR accesses are directed to a specific CPU on multi-processor
1061 systems.
1063 config X86_CPUID
1064 tristate "/dev/cpu/*/cpuid - CPU information support"
1065 ---help---
1066 This device gives processes access to the x86 CPUID instruction to
1067 be executed on a specific processor. It is a character device
1068 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1069 /dev/cpu/31/cpuid.
1071 choice
1072 prompt "High Memory Support"
1073 default HIGHMEM4G
1074 depends on X86_32
1076 config NOHIGHMEM
1077 bool "off"
1078 ---help---
1079 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1080 However, the address space of 32-bit x86 processors is only 4
1081 Gigabytes large. That means that, if you have a large amount of
1082 physical memory, not all of it can be "permanently mapped" by the
1083 kernel. The physical memory that's not permanently mapped is called
1084 "high memory".
1086 If you are compiling a kernel which will never run on a machine with
1087 more than 1 Gigabyte total physical RAM, answer "off" here (default
1088 choice and suitable for most users). This will result in a "3GB/1GB"
1089 split: 3GB are mapped so that each process sees a 3GB virtual memory
1090 space and the remaining part of the 4GB virtual memory space is used
1091 by the kernel to permanently map as much physical memory as
1092 possible.
1094 If the machine has between 1 and 4 Gigabytes physical RAM, then
1095 answer "4GB" here.
1097 If more than 4 Gigabytes is used then answer "64GB" here. This
1098 selection turns Intel PAE (Physical Address Extension) mode on.
1099 PAE implements 3-level paging on IA32 processors. PAE is fully
1100 supported by Linux, PAE mode is implemented on all recent Intel
1101 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1102 then the kernel will not boot on CPUs that don't support PAE!
1104 The actual amount of total physical memory will either be
1105 auto detected or can be forced by using a kernel command line option
1106 such as "mem=256M". (Try "man bootparam" or see the documentation of
1107 your boot loader (lilo or loadlin) about how to pass options to the
1108 kernel at boot time.)
1110 If unsure, say "off".
1112 config HIGHMEM4G
1113 bool "4GB"
1114 ---help---
1115 Select this if you have a 32-bit processor and between 1 and 4
1116 gigabytes of physical RAM.
1118 config HIGHMEM64G
1119 bool "64GB"
1120 depends on !M486
1121 select X86_PAE
1122 ---help---
1123 Select this if you have a 32-bit processor and more than 4
1124 gigabytes of physical RAM.
1126 endchoice
1128 choice
1129 prompt "Memory split" if EXPERT
1130 default VMSPLIT_3G
1131 depends on X86_32
1132 ---help---
1133 Select the desired split between kernel and user memory.
1135 If the address range available to the kernel is less than the
1136 physical memory installed, the remaining memory will be available
1137 as "high memory". Accessing high memory is a little more costly
1138 than low memory, as it needs to be mapped into the kernel first.
1139 Note that increasing the kernel address space limits the range
1140 available to user programs, making the address space there
1141 tighter. Selecting anything other than the default 3G/1G split
1142 will also likely make your kernel incompatible with binary-only
1143 kernel modules.
1145 If you are not absolutely sure what you are doing, leave this
1146 option alone!
1148 config VMSPLIT_3G
1149 bool "3G/1G user/kernel split"
1150 config VMSPLIT_3G_OPT
1151 depends on !X86_PAE
1152 bool "3G/1G user/kernel split (for full 1G low memory)"
1153 config VMSPLIT_2G
1154 bool "2G/2G user/kernel split"
1155 config VMSPLIT_2G_OPT
1156 depends on !X86_PAE
1157 bool "2G/2G user/kernel split (for full 2G low memory)"
1158 config VMSPLIT_1G
1159 bool "1G/3G user/kernel split"
1160 endchoice
1162 config PAGE_OFFSET
1163 hex
1164 default 0xB0000000 if VMSPLIT_3G_OPT
1165 default 0x80000000 if VMSPLIT_2G
1166 default 0x78000000 if VMSPLIT_2G_OPT
1167 default 0x40000000 if VMSPLIT_1G
1168 default 0xC0000000
1169 depends on X86_32
1171 config HIGHMEM
1172 def_bool y
1173 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1175 config X86_PAE
1176 bool "PAE (Physical Address Extension) Support"
1177 depends on X86_32 && !HIGHMEM4G
1178 ---help---
1179 PAE is required for NX support, and furthermore enables
1180 larger swapspace support for non-overcommit purposes. It
1181 has the cost of more pagetable lookup overhead, and also
1182 consumes more pagetable space per process.
1184 config ARCH_PHYS_ADDR_T_64BIT
1185 def_bool y
1186 depends on X86_64 || X86_PAE
1188 config ARCH_DMA_ADDR_T_64BIT
1189 def_bool y
1190 depends on X86_64 || HIGHMEM64G
1192 config DIRECT_GBPAGES
1193 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1194 default y
1195 depends on X86_64
1196 ---help---
1197 Allow the kernel linear mapping to use 1GB pages on CPUs that
1198 support it. This can improve the kernel's performance a tiny bit by
1199 reducing TLB pressure. If in doubt, say "Y".
1201 # Common NUMA Features
1202 config NUMA
1203 bool "Numa Memory Allocation and Scheduler Support"
1204 depends on SMP
1205 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1206 default y if X86_BIGSMP
1207 ---help---
1208 Enable NUMA (Non Uniform Memory Access) support.
1210 The kernel will try to allocate memory used by a CPU on the
1211 local memory controller of the CPU and add some more
1212 NUMA awareness to the kernel.
1214 For 64-bit this is recommended if the system is Intel Core i7
1215 (or later), AMD Opteron, or EM64T NUMA.
1217 For 32-bit this is only needed if you boot a 32-bit
1218 kernel on a 64-bit NUMA platform.
1220 Otherwise, you should say N.
1222 config AMD_NUMA
1223 def_bool y
1224 prompt "Old style AMD Opteron NUMA detection"
1225 depends on X86_64 && NUMA && PCI
1226 ---help---
1227 Enable AMD NUMA node topology detection. You should say Y here if
1228 you have a multi processor AMD system. This uses an old method to
1229 read the NUMA configuration directly from the builtin Northbridge
1230 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1231 which also takes priority if both are compiled in.
1233 config X86_64_ACPI_NUMA
1234 def_bool y
1235 prompt "ACPI NUMA detection"
1236 depends on X86_64 && NUMA && ACPI && PCI
1237 select ACPI_NUMA
1238 ---help---
1239 Enable ACPI SRAT based node topology detection.
1241 # Some NUMA nodes have memory ranges that span
1242 # other nodes. Even though a pfn is valid and
1243 # between a node's start and end pfns, it may not
1244 # reside on that node. See memmap_init_zone()
1245 # for details.
1246 config NODES_SPAN_OTHER_NODES
1247 def_bool y
1248 depends on X86_64_ACPI_NUMA
1250 config NUMA_EMU
1251 bool "NUMA emulation"
1252 depends on NUMA
1253 ---help---
1254 Enable NUMA emulation. A flat machine will be split
1255 into virtual nodes when booted with "numa=fake=N", where N is the
1256 number of nodes. This is only useful for debugging.
1258 config NODES_SHIFT
1259 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1260 range 1 10
1261 default "10" if MAXSMP
1262 default "6" if X86_64
1263 default "3"
1264 depends on NEED_MULTIPLE_NODES
1265 ---help---
1266 Specify the maximum number of NUMA Nodes available on the target
1267 system. Increases memory reserved to accommodate various tables.
1269 config ARCH_HAVE_MEMORY_PRESENT
1270 def_bool y
1271 depends on X86_32 && DISCONTIGMEM
1273 config NEED_NODE_MEMMAP_SIZE
1274 def_bool y
1275 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1277 config ARCH_FLATMEM_ENABLE
1278 def_bool y
1279 depends on X86_32 && !NUMA
1281 config ARCH_DISCONTIGMEM_ENABLE
1282 def_bool y
1283 depends on NUMA && X86_32
1285 config ARCH_DISCONTIGMEM_DEFAULT
1286 def_bool y
1287 depends on NUMA && X86_32
1289 config ARCH_SPARSEMEM_ENABLE
1290 def_bool y
1291 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1292 select SPARSEMEM_STATIC if X86_32
1293 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1295 config ARCH_SPARSEMEM_DEFAULT
1296 def_bool y
1297 depends on X86_64
1299 config ARCH_SELECT_MEMORY_MODEL
1300 def_bool y
1301 depends on ARCH_SPARSEMEM_ENABLE
1303 config ARCH_MEMORY_PROBE
1304 bool "Enable sysfs memory/probe interface"
1305 depends on X86_64 && MEMORY_HOTPLUG
1306 help
1307 This option enables a sysfs memory/probe interface for testing.
1308 See Documentation/memory-hotplug.txt for more information.
1309 If you are unsure how to answer this question, answer N.
1311 config ARCH_PROC_KCORE_TEXT
1312 def_bool y
1313 depends on X86_64 && PROC_KCORE
1315 config ILLEGAL_POINTER_VALUE
1316 hex
1317 default 0 if X86_32
1318 default 0xdead000000000000 if X86_64
1320 source "mm/Kconfig"
1322 config HIGHPTE
1323 bool "Allocate 3rd-level pagetables from highmem"
1324 depends on HIGHMEM
1325 ---help---
1326 The VM uses one page table entry for each page of physical memory.
1327 For systems with a lot of RAM, this can be wasteful of precious
1328 low memory. Setting this option will put user-space page table
1329 entries in high memory.
1331 config X86_CHECK_BIOS_CORRUPTION
1332 bool "Check for low memory corruption"
1333 ---help---
1334 Periodically check for memory corruption in low memory, which
1335 is suspected to be caused by BIOS. Even when enabled in the
1336 configuration, it is disabled at runtime. Enable it by
1337 setting "memory_corruption_check=1" on the kernel command
1338 line. By default it scans the low 64k of memory every 60
1339 seconds; see the memory_corruption_check_size and
1340 memory_corruption_check_period parameters in
1341 Documentation/kernel-parameters.txt to adjust this.
1343 When enabled with the default parameters, this option has
1344 almost no overhead, as it reserves a relatively small amount
1345 of memory and scans it infrequently. It both detects corruption
1346 and prevents it from affecting the running system.
1348 It is, however, intended as a diagnostic tool; if repeatable
1349 BIOS-originated corruption always affects the same memory,
1350 you can use memmap= to prevent the kernel from using that
1351 memory.
1353 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1354 bool "Set the default setting of memory_corruption_check"
1355 depends on X86_CHECK_BIOS_CORRUPTION
1356 default y
1357 ---help---
1358 Set whether the default state of memory_corruption_check is
1359 on or off.
1361 config X86_RESERVE_LOW
1362 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1363 default 64
1364 range 4 640
1365 ---help---
1366 Specify the amount of low memory to reserve for the BIOS.
1368 The first page contains BIOS data structures that the kernel
1369 must not use, so that page must always be reserved.
1371 By default we reserve the first 64K of physical RAM, as a
1372 number of BIOSes are known to corrupt that memory range
1373 during events such as suspend/resume or monitor cable
1374 insertion, so it must not be used by the kernel.
1376 You can set this to 4 if you are absolutely sure that you
1377 trust the BIOS to get all its memory reservations and usages
1378 right. If you know your BIOS have problems beyond the
1379 default 64K area, you can set this to 640 to avoid using the
1380 entire low memory range.
1382 If you have doubts about the BIOS (e.g. suspend/resume does
1383 not work or there's kernel crashes after certain hardware
1384 hotplug events) then you might want to enable
1385 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1386 typical corruption patterns.
1388 Leave this to the default value of 64 if you are unsure.
1390 config MATH_EMULATION
1391 bool
1392 prompt "Math emulation" if X86_32
1393 ---help---
1394 Linux can emulate a math coprocessor (used for floating point
1395 operations) if you don't have one. 486DX and Pentium processors have
1396 a math coprocessor built in, 486SX and 386 do not, unless you added
1397 a 487DX or 387, respectively. (The messages during boot time can
1398 give you some hints here ["man dmesg"].) Everyone needs either a
1399 coprocessor or this emulation.
1401 If you don't have a math coprocessor, you need to say Y here; if you
1402 say Y here even though you have a coprocessor, the coprocessor will
1403 be used nevertheless. (This behavior can be changed with the kernel
1404 command line option "no387", which comes handy if your coprocessor
1405 is broken. Try "man bootparam" or see the documentation of your boot
1406 loader (lilo or loadlin) about how to pass options to the kernel at
1407 boot time.) This means that it is a good idea to say Y here if you
1408 intend to use this kernel on different machines.
1410 More information about the internals of the Linux math coprocessor
1411 emulation can be found in <file:arch/x86/math-emu/README>.
1413 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1414 kernel, it won't hurt.
1416 config MTRR
1417 def_bool y
1418 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1419 ---help---
1420 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1421 the Memory Type Range Registers (MTRRs) may be used to control
1422 processor access to memory ranges. This is most useful if you have
1423 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1424 allows bus write transfers to be combined into a larger transfer
1425 before bursting over the PCI/AGP bus. This can increase performance
1426 of image write operations 2.5 times or more. Saying Y here creates a
1427 /proc/mtrr file which may be used to manipulate your processor's
1428 MTRRs. Typically the X server should use this.
1430 This code has a reasonably generic interface so that similar
1431 control registers on other processors can be easily supported
1432 as well:
1434 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1435 Registers (ARRs) which provide a similar functionality to MTRRs. For
1436 these, the ARRs are used to emulate the MTRRs.
1437 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1438 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1439 write-combining. All of these processors are supported by this code
1440 and it makes sense to say Y here if you have one of them.
1442 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1443 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1444 can lead to all sorts of problems, so it's good to say Y here.
1446 You can safely say Y even if your machine doesn't have MTRRs, you'll
1447 just add about 9 KB to your kernel.
1449 See <file:Documentation/x86/mtrr.txt> for more information.
1451 config MTRR_SANITIZER
1452 def_bool y
1453 prompt "MTRR cleanup support"
1454 depends on MTRR
1455 ---help---
1456 Convert MTRR layout from continuous to discrete, so X drivers can
1457 add writeback entries.
1459 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1460 The largest mtrr entry size for a continuous block can be set with
1461 mtrr_chunk_size.
1463 If unsure, say Y.
1465 config MTRR_SANITIZER_ENABLE_DEFAULT
1466 int "MTRR cleanup enable value (0-1)"
1467 range 0 1
1468 default "0"
1469 depends on MTRR_SANITIZER
1470 ---help---
1471 Enable mtrr cleanup default value
1473 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1474 int "MTRR cleanup spare reg num (0-7)"
1475 range 0 7
1476 default "1"
1477 depends on MTRR_SANITIZER
1478 ---help---
1479 mtrr cleanup spare entries default, it can be changed via
1480 mtrr_spare_reg_nr=N on the kernel command line.
1482 config X86_PAT
1483 def_bool y
1484 prompt "x86 PAT support" if EXPERT
1485 depends on MTRR
1486 ---help---
1487 Use PAT attributes to setup page level cache control.
1489 PATs are the modern equivalents of MTRRs and are much more
1490 flexible than MTRRs.
1492 Say N here if you see bootup problems (boot crash, boot hang,
1493 spontaneous reboots) or a non-working video driver.
1495 If unsure, say Y.
1497 config ARCH_USES_PG_UNCACHED
1498 def_bool y
1499 depends on X86_PAT
1501 config ARCH_RANDOM
1502 def_bool y
1503 prompt "x86 architectural random number generator" if EXPERT
1504 ---help---
1505 Enable the x86 architectural RDRAND instruction
1506 (Intel Bull Mountain technology) to generate random numbers.
1507 If supported, this is a high bandwidth, cryptographically
1508 secure hardware random number generator.
1510 config X86_SMAP
1511 def_bool y
1512 prompt "Supervisor Mode Access Prevention" if EXPERT
1513 ---help---
1514 Supervisor Mode Access Prevention (SMAP) is a security
1515 feature in newer Intel processors. There is a small
1516 performance cost if this enabled and turned on; there is
1517 also a small increase in the kernel size if this is enabled.
1519 If unsure, say Y.
1521 config EFI
1522 bool "EFI runtime service support"
1523 depends on ACPI
1524 select UCS2_STRING
1525 ---help---
1526 This enables the kernel to use EFI runtime services that are
1527 available (such as the EFI variable services).
1529 This option is only useful on systems that have EFI firmware.
1530 In addition, you should use the latest ELILO loader available
1531 at <http://elilo.sourceforge.net> in order to take advantage
1532 of EFI runtime services. However, even with this option, the
1533 resultant kernel should continue to boot on existing non-EFI
1534 platforms.
1536 config EFI_STUB
1537 bool "EFI stub support"
1538 depends on EFI
1539 ---help---
1540 This kernel feature allows a bzImage to be loaded directly
1541 by EFI firmware without the use of a bootloader.
1543 See Documentation/efi-stub.txt for more information.
1545 config EFI_MIXED
1546 bool "EFI mixed-mode support"
1547 depends on EFI_STUB && X86_64
1548 ---help---
1549 Enabling this feature allows a 64-bit kernel to be booted
1550 on a 32-bit firmware, provided that your CPU supports 64-bit
1551 mode.
1553 Note that it is not possible to boot a mixed-mode enabled
1554 kernel via the EFI boot stub - a bootloader that supports
1555 the EFI handover protocol must be used.
1557 If unsure, say N.
1559 config SECCOMP
1560 def_bool y
1561 prompt "Enable seccomp to safely compute untrusted bytecode"
1562 ---help---
1563 This kernel feature is useful for number crunching applications
1564 that may need to compute untrusted bytecode during their
1565 execution. By using pipes or other transports made available to
1566 the process as file descriptors supporting the read/write
1567 syscalls, it's possible to isolate those applications in
1568 their own address space using seccomp. Once seccomp is
1569 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1570 and the task is only allowed to execute a few safe syscalls
1571 defined by each seccomp mode.
1573 If unsure, say Y. Only embedded should say N here.
1575 source kernel/Kconfig.hz
1577 config KEXEC
1578 bool "kexec system call"
1579 ---help---
1580 kexec is a system call that implements the ability to shutdown your
1581 current kernel, and to start another kernel. It is like a reboot
1582 but it is independent of the system firmware. And like a reboot
1583 you can start any kernel with it, not just Linux.
1585 The name comes from the similarity to the exec system call.
1587 It is an ongoing process to be certain the hardware in a machine
1588 is properly shutdown, so do not be surprised if this code does not
1589 initially work for you. As of this writing the exact hardware
1590 interface is strongly in flux, so no good recommendation can be
1591 made.
1593 config CRASH_DUMP
1594 bool "kernel crash dumps"
1595 depends on X86_64 || (X86_32 && HIGHMEM)
1596 ---help---
1597 Generate crash dump after being started by kexec.
1598 This should be normally only set in special crash dump kernels
1599 which are loaded in the main kernel with kexec-tools into
1600 a specially reserved region and then later executed after
1601 a crash by kdump/kexec. The crash dump kernel must be compiled
1602 to a memory address not used by the main kernel or BIOS using
1603 PHYSICAL_START, or it must be built as a relocatable image
1604 (CONFIG_RELOCATABLE=y).
1605 For more details see Documentation/kdump/kdump.txt
1607 config KEXEC_JUMP
1608 bool "kexec jump"
1609 depends on KEXEC && HIBERNATION
1610 ---help---
1611 Jump between original kernel and kexeced kernel and invoke
1612 code in physical address mode via KEXEC
1614 config PHYSICAL_START
1615 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1616 default "0x1000000"
1617 ---help---
1618 This gives the physical address where the kernel is loaded.
1620 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1621 bzImage will decompress itself to above physical address and
1622 run from there. Otherwise, bzImage will run from the address where
1623 it has been loaded by the boot loader and will ignore above physical
1624 address.
1626 In normal kdump cases one does not have to set/change this option
1627 as now bzImage can be compiled as a completely relocatable image
1628 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1629 address. This option is mainly useful for the folks who don't want
1630 to use a bzImage for capturing the crash dump and want to use a
1631 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1632 to be specifically compiled to run from a specific memory area
1633 (normally a reserved region) and this option comes handy.
1635 So if you are using bzImage for capturing the crash dump,
1636 leave the value here unchanged to 0x1000000 and set
1637 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1638 for capturing the crash dump change this value to start of
1639 the reserved region. In other words, it can be set based on
1640 the "X" value as specified in the "crashkernel=YM@XM"
1641 command line boot parameter passed to the panic-ed
1642 kernel. Please take a look at Documentation/kdump/kdump.txt
1643 for more details about crash dumps.
1645 Usage of bzImage for capturing the crash dump is recommended as
1646 one does not have to build two kernels. Same kernel can be used
1647 as production kernel and capture kernel. Above option should have
1648 gone away after relocatable bzImage support is introduced. But it
1649 is present because there are users out there who continue to use
1650 vmlinux for dump capture. This option should go away down the
1651 line.
1653 Don't change this unless you know what you are doing.
1655 config RELOCATABLE
1656 bool "Build a relocatable kernel"
1657 default y
1658 ---help---
1659 This builds a kernel image that retains relocation information
1660 so it can be loaded someplace besides the default 1MB.
1661 The relocations tend to make the kernel binary about 10% larger,
1662 but are discarded at runtime.
1664 One use is for the kexec on panic case where the recovery kernel
1665 must live at a different physical address than the primary
1666 kernel.
1668 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1669 it has been loaded at and the compile time physical address
1670 (CONFIG_PHYSICAL_START) is used as the minimum location.
1672 config RANDOMIZE_BASE
1673 bool "Randomize the address of the kernel image"
1674 depends on RELOCATABLE
1675 depends on !HIBERNATION
1676 default n
1677 ---help---
1678 Randomizes the physical and virtual address at which the
1679 kernel image is decompressed, as a security feature that
1680 deters exploit attempts relying on knowledge of the location
1681 of kernel internals.
1683 Entropy is generated using the RDRAND instruction if it is
1684 supported. If RDTSC is supported, it is used as well. If
1685 neither RDRAND nor RDTSC are supported, then randomness is
1686 read from the i8254 timer.
1688 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1689 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1690 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1691 minimum of 2MiB, only 10 bits of entropy is theoretically
1692 possible. At best, due to page table layouts, 64-bit can use
1693 9 bits of entropy and 32-bit uses 8 bits.
1695 If unsure, say N.
1697 config RANDOMIZE_BASE_MAX_OFFSET
1698 hex "Maximum kASLR offset allowed" if EXPERT
1699 depends on RANDOMIZE_BASE
1700 range 0x0 0x20000000 if X86_32
1701 default "0x20000000" if X86_32
1702 range 0x0 0x40000000 if X86_64
1703 default "0x40000000" if X86_64
1704 ---help---
1705 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1706 memory is used to determine the maximal offset in bytes that will
1707 be applied to the kernel when kernel Address Space Layout
1708 Randomization (kASLR) is active. This must be a multiple of
1709 PHYSICAL_ALIGN.
1711 On 32-bit this is limited to 512MiB by page table layouts. The
1712 default is 512MiB.
1714 On 64-bit this is limited by how the kernel fixmap page table is
1715 positioned, so this cannot be larger than 1GiB currently. Without
1716 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1717 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1718 modules area will shrink to compensate, up to the current maximum
1719 1GiB to 1GiB split. The default is 1GiB.
1721 If unsure, leave at the default value.
1723 # Relocation on x86 needs some additional build support
1724 config X86_NEED_RELOCS
1725 def_bool y
1726 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1728 config PHYSICAL_ALIGN
1729 hex "Alignment value to which kernel should be aligned"
1730 default "0x200000"
1731 range 0x2000 0x1000000 if X86_32
1732 range 0x200000 0x1000000 if X86_64
1733 ---help---
1734 This value puts the alignment restrictions on physical address
1735 where kernel is loaded and run from. Kernel is compiled for an
1736 address which meets above alignment restriction.
1738 If bootloader loads the kernel at a non-aligned address and
1739 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1740 address aligned to above value and run from there.
1742 If bootloader loads the kernel at a non-aligned address and
1743 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1744 load address and decompress itself to the address it has been
1745 compiled for and run from there. The address for which kernel is
1746 compiled already meets above alignment restrictions. Hence the
1747 end result is that kernel runs from a physical address meeting
1748 above alignment restrictions.
1750 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1751 this value must be a multiple of 0x200000.
1753 Don't change this unless you know what you are doing.
1755 config HOTPLUG_CPU
1756 bool "Support for hot-pluggable CPUs"
1757 depends on SMP
1758 ---help---
1759 Say Y here to allow turning CPUs off and on. CPUs can be
1760 controlled through /sys/devices/system/cpu.
1761 ( Note: power management support will enable this option
1762 automatically on SMP systems. )
1763 Say N if you want to disable CPU hotplug.
1765 config BOOTPARAM_HOTPLUG_CPU0
1766 bool "Set default setting of cpu0_hotpluggable"
1767 default n
1768 depends on HOTPLUG_CPU
1769 ---help---
1770 Set whether default state of cpu0_hotpluggable is on or off.
1772 Say Y here to enable CPU0 hotplug by default. If this switch
1773 is turned on, there is no need to give cpu0_hotplug kernel
1774 parameter and the CPU0 hotplug feature is enabled by default.
1776 Please note: there are two known CPU0 dependencies if you want
1777 to enable the CPU0 hotplug feature either by this switch or by
1778 cpu0_hotplug kernel parameter.
1780 First, resume from hibernate or suspend always starts from CPU0.
1781 So hibernate and suspend are prevented if CPU0 is offline.
1783 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1784 offline if any interrupt can not migrate out of CPU0. There may
1785 be other CPU0 dependencies.
1787 Please make sure the dependencies are under your control before
1788 you enable this feature.
1790 Say N if you don't want to enable CPU0 hotplug feature by default.
1791 You still can enable the CPU0 hotplug feature at boot by kernel
1792 parameter cpu0_hotplug.
1794 config DEBUG_HOTPLUG_CPU0
1795 def_bool n
1796 prompt "Debug CPU0 hotplug"
1797 depends on HOTPLUG_CPU
1798 ---help---
1799 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1800 soon as possible and boots up userspace with CPU0 offlined. User
1801 can online CPU0 back after boot time.
1803 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1804 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1805 compilation or giving cpu0_hotplug kernel parameter at boot.
1807 If unsure, say N.
1809 config COMPAT_VDSO
1810 def_bool n
1811 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1812 depends on X86_32 || IA32_EMULATION
1813 ---help---
1814 Certain buggy versions of glibc will crash if they are
1815 presented with a 32-bit vDSO that is not mapped at the address
1816 indicated in its segment table.
1818 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1819 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1820 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1821 the only released version with the bug, but OpenSUSE 9
1822 contains a buggy "glibc 2.3.2".
1824 The symptom of the bug is that everything crashes on startup, saying:
1825 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1827 Saying Y here changes the default value of the vdso32 boot
1828 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1829 This works around the glibc bug but hurts performance.
1831 If unsure, say N: if you are compiling your own kernel, you
1832 are unlikely to be using a buggy version of glibc.
1834 config CMDLINE_BOOL
1835 bool "Built-in kernel command line"
1836 ---help---
1837 Allow for specifying boot arguments to the kernel at
1838 build time. On some systems (e.g. embedded ones), it is
1839 necessary or convenient to provide some or all of the
1840 kernel boot arguments with the kernel itself (that is,
1841 to not rely on the boot loader to provide them.)
1843 To compile command line arguments into the kernel,
1844 set this option to 'Y', then fill in the
1845 the boot arguments in CONFIG_CMDLINE.
1847 Systems with fully functional boot loaders (i.e. non-embedded)
1848 should leave this option set to 'N'.
1850 config CMDLINE
1851 string "Built-in kernel command string"
1852 depends on CMDLINE_BOOL
1853 default ""
1854 ---help---
1855 Enter arguments here that should be compiled into the kernel
1856 image and used at boot time. If the boot loader provides a
1857 command line at boot time, it is appended to this string to
1858 form the full kernel command line, when the system boots.
1860 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1861 change this behavior.
1863 In most cases, the command line (whether built-in or provided
1864 by the boot loader) should specify the device for the root
1865 file system.
1867 config CMDLINE_OVERRIDE
1868 bool "Built-in command line overrides boot loader arguments"
1869 depends on CMDLINE_BOOL
1870 ---help---
1871 Set this option to 'Y' to have the kernel ignore the boot loader
1872 command line, and use ONLY the built-in command line.
1874 This is used to work around broken boot loaders. This should
1875 be set to 'N' under normal conditions.
1877 endmenu
1879 config ARCH_ENABLE_MEMORY_HOTPLUG
1880 def_bool y
1881 depends on X86_64 || (X86_32 && HIGHMEM)
1883 config ARCH_ENABLE_MEMORY_HOTREMOVE
1884 def_bool y
1885 depends on MEMORY_HOTPLUG
1887 config USE_PERCPU_NUMA_NODE_ID
1888 def_bool y
1889 depends on NUMA
1891 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1892 def_bool y
1893 depends on X86_64 || X86_PAE
1895 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1896 def_bool y
1897 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1899 menu "Power management and ACPI options"
1901 config ARCH_HIBERNATION_HEADER
1902 def_bool y
1903 depends on X86_64 && HIBERNATION
1905 source "kernel/power/Kconfig"
1907 source "drivers/acpi/Kconfig"
1909 source "drivers/sfi/Kconfig"
1911 config X86_APM_BOOT
1912 def_bool y
1913 depends on APM
1915 menuconfig APM
1916 tristate "APM (Advanced Power Management) BIOS support"
1917 depends on X86_32 && PM_SLEEP
1918 ---help---
1919 APM is a BIOS specification for saving power using several different
1920 techniques. This is mostly useful for battery powered laptops with
1921 APM compliant BIOSes. If you say Y here, the system time will be
1922 reset after a RESUME operation, the /proc/apm device will provide
1923 battery status information, and user-space programs will receive
1924 notification of APM "events" (e.g. battery status change).
1926 If you select "Y" here, you can disable actual use of the APM
1927 BIOS by passing the "apm=off" option to the kernel at boot time.
1929 Note that the APM support is almost completely disabled for
1930 machines with more than one CPU.
1932 In order to use APM, you will need supporting software. For location
1933 and more information, read <file:Documentation/power/apm-acpi.txt>
1934 and the Battery Powered Linux mini-HOWTO, available from
1935 <http://www.tldp.org/docs.html#howto>.
1937 This driver does not spin down disk drives (see the hdparm(8)
1938 manpage ("man 8 hdparm") for that), and it doesn't turn off
1939 VESA-compliant "green" monitors.
1941 This driver does not support the TI 4000M TravelMate and the ACER
1942 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1943 desktop machines also don't have compliant BIOSes, and this driver
1944 may cause those machines to panic during the boot phase.
1946 Generally, if you don't have a battery in your machine, there isn't
1947 much point in using this driver and you should say N. If you get
1948 random kernel OOPSes or reboots that don't seem to be related to
1949 anything, try disabling/enabling this option (or disabling/enabling
1950 APM in your BIOS).
1952 Some other things you should try when experiencing seemingly random,
1953 "weird" problems:
1955 1) make sure that you have enough swap space and that it is
1956 enabled.
1957 2) pass the "no-hlt" option to the kernel
1958 3) switch on floating point emulation in the kernel and pass
1959 the "no387" option to the kernel
1960 4) pass the "floppy=nodma" option to the kernel
1961 5) pass the "mem=4M" option to the kernel (thereby disabling
1962 all but the first 4 MB of RAM)
1963 6) make sure that the CPU is not over clocked.
1964 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1965 8) disable the cache from your BIOS settings
1966 9) install a fan for the video card or exchange video RAM
1967 10) install a better fan for the CPU
1968 11) exchange RAM chips
1969 12) exchange the motherboard.
1971 To compile this driver as a module, choose M here: the
1972 module will be called apm.
1974 if APM
1976 config APM_IGNORE_USER_SUSPEND
1977 bool "Ignore USER SUSPEND"
1978 ---help---
1979 This option will ignore USER SUSPEND requests. On machines with a
1980 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1981 series notebooks, it is necessary to say Y because of a BIOS bug.
1983 config APM_DO_ENABLE
1984 bool "Enable PM at boot time"
1985 ---help---
1986 Enable APM features at boot time. From page 36 of the APM BIOS
1987 specification: "When disabled, the APM BIOS does not automatically
1988 power manage devices, enter the Standby State, enter the Suspend
1989 State, or take power saving steps in response to CPU Idle calls."
1990 This driver will make CPU Idle calls when Linux is idle (unless this
1991 feature is turned off -- see "Do CPU IDLE calls", below). This
1992 should always save battery power, but more complicated APM features
1993 will be dependent on your BIOS implementation. You may need to turn
1994 this option off if your computer hangs at boot time when using APM
1995 support, or if it beeps continuously instead of suspending. Turn
1996 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1997 T400CDT. This is off by default since most machines do fine without
1998 this feature.
2000 config APM_CPU_IDLE
2001 depends on CPU_IDLE
2002 bool "Make CPU Idle calls when idle"
2003 ---help---
2004 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2005 On some machines, this can activate improved power savings, such as
2006 a slowed CPU clock rate, when the machine is idle. These idle calls
2007 are made after the idle loop has run for some length of time (e.g.,
2008 333 mS). On some machines, this will cause a hang at boot time or
2009 whenever the CPU becomes idle. (On machines with more than one CPU,
2010 this option does nothing.)
2012 config APM_DISPLAY_BLANK
2013 bool "Enable console blanking using APM"
2014 ---help---
2015 Enable console blanking using the APM. Some laptops can use this to
2016 turn off the LCD backlight when the screen blanker of the Linux
2017 virtual console blanks the screen. Note that this is only used by
2018 the virtual console screen blanker, and won't turn off the backlight
2019 when using the X Window system. This also doesn't have anything to
2020 do with your VESA-compliant power-saving monitor. Further, this
2021 option doesn't work for all laptops -- it might not turn off your
2022 backlight at all, or it might print a lot of errors to the console,
2023 especially if you are using gpm.
2025 config APM_ALLOW_INTS
2026 bool "Allow interrupts during APM BIOS calls"
2027 ---help---
2028 Normally we disable external interrupts while we are making calls to
2029 the APM BIOS as a measure to lessen the effects of a badly behaving
2030 BIOS implementation. The BIOS should reenable interrupts if it
2031 needs to. Unfortunately, some BIOSes do not -- especially those in
2032 many of the newer IBM Thinkpads. If you experience hangs when you
2033 suspend, try setting this to Y. Otherwise, say N.
2035 endif # APM
2037 source "drivers/cpufreq/Kconfig"
2039 source "drivers/cpuidle/Kconfig"
2041 source "drivers/idle/Kconfig"
2043 endmenu
2046 menu "Bus options (PCI etc.)"
2048 config PCI
2049 bool "PCI support"
2050 default y
2051 ---help---
2052 Find out whether you have a PCI motherboard. PCI is the name of a
2053 bus system, i.e. the way the CPU talks to the other stuff inside
2054 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2055 VESA. If you have PCI, say Y, otherwise N.
2057 choice
2058 prompt "PCI access mode"
2059 depends on X86_32 && PCI
2060 default PCI_GOANY
2061 ---help---
2062 On PCI systems, the BIOS can be used to detect the PCI devices and
2063 determine their configuration. However, some old PCI motherboards
2064 have BIOS bugs and may crash if this is done. Also, some embedded
2065 PCI-based systems don't have any BIOS at all. Linux can also try to
2066 detect the PCI hardware directly without using the BIOS.
2068 With this option, you can specify how Linux should detect the
2069 PCI devices. If you choose "BIOS", the BIOS will be used,
2070 if you choose "Direct", the BIOS won't be used, and if you
2071 choose "MMConfig", then PCI Express MMCONFIG will be used.
2072 If you choose "Any", the kernel will try MMCONFIG, then the
2073 direct access method and falls back to the BIOS if that doesn't
2074 work. If unsure, go with the default, which is "Any".
2076 config PCI_GOBIOS
2077 bool "BIOS"
2079 config PCI_GOMMCONFIG
2080 bool "MMConfig"
2082 config PCI_GODIRECT
2083 bool "Direct"
2085 config PCI_GOOLPC
2086 bool "OLPC XO-1"
2087 depends on OLPC
2089 config PCI_GOANY
2090 bool "Any"
2092 endchoice
2094 config PCI_BIOS
2095 def_bool y
2096 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2098 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2099 config PCI_DIRECT
2100 def_bool y
2101 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2103 config PCI_MMCONFIG
2104 def_bool y
2105 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2107 config PCI_OLPC
2108 def_bool y
2109 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2111 config PCI_XEN
2112 def_bool y
2113 depends on PCI && XEN
2114 select SWIOTLB_XEN
2116 config PCI_DOMAINS
2117 def_bool y
2118 depends on PCI
2120 config PCI_MMCONFIG
2121 bool "Support mmconfig PCI config space access"
2122 depends on X86_64 && PCI && ACPI
2124 config PCI_CNB20LE_QUIRK
2125 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2126 depends on PCI
2127 help
2128 Read the PCI windows out of the CNB20LE host bridge. This allows
2129 PCI hotplug to work on systems with the CNB20LE chipset which do
2130 not have ACPI.
2132 There's no public spec for this chipset, and this functionality
2133 is known to be incomplete.
2135 You should say N unless you know you need this.
2137 source "drivers/pci/pcie/Kconfig"
2139 source "drivers/pci/Kconfig"
2141 # x86_64 have no ISA slots, but can have ISA-style DMA.
2142 config ISA_DMA_API
2143 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2144 default y
2145 help
2146 Enables ISA-style DMA support for devices requiring such controllers.
2147 If unsure, say Y.
2149 if X86_32
2151 config ISA
2152 bool "ISA support"
2153 ---help---
2154 Find out whether you have ISA slots on your motherboard. ISA is the
2155 name of a bus system, i.e. the way the CPU talks to the other stuff
2156 inside your box. Other bus systems are PCI, EISA, MicroChannel
2157 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2158 newer boards don't support it. If you have ISA, say Y, otherwise N.
2160 config EISA
2161 bool "EISA support"
2162 depends on ISA
2163 ---help---
2164 The Extended Industry Standard Architecture (EISA) bus was
2165 developed as an open alternative to the IBM MicroChannel bus.
2167 The EISA bus provided some of the features of the IBM MicroChannel
2168 bus while maintaining backward compatibility with cards made for
2169 the older ISA bus. The EISA bus saw limited use between 1988 and
2170 1995 when it was made obsolete by the PCI bus.
2172 Say Y here if you are building a kernel for an EISA-based machine.
2174 Otherwise, say N.
2176 source "drivers/eisa/Kconfig"
2178 config SCx200
2179 tristate "NatSemi SCx200 support"
2180 ---help---
2181 This provides basic support for National Semiconductor's
2182 (now AMD's) Geode processors. The driver probes for the
2183 PCI-IDs of several on-chip devices, so its a good dependency
2184 for other scx200_* drivers.
2186 If compiled as a module, the driver is named scx200.
2188 config SCx200HR_TIMER
2189 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2190 depends on SCx200
2191 default y
2192 ---help---
2193 This driver provides a clocksource built upon the on-chip
2194 27MHz high-resolution timer. Its also a workaround for
2195 NSC Geode SC-1100's buggy TSC, which loses time when the
2196 processor goes idle (as is done by the scheduler). The
2197 other workaround is idle=poll boot option.
2199 config OLPC
2200 bool "One Laptop Per Child support"
2201 depends on !X86_PAE
2202 select GPIOLIB
2203 select OF
2204 select OF_PROMTREE
2205 select IRQ_DOMAIN
2206 ---help---
2207 Add support for detecting the unique features of the OLPC
2208 XO hardware.
2210 config OLPC_XO1_PM
2211 bool "OLPC XO-1 Power Management"
2212 depends on OLPC && MFD_CS5535 && PM_SLEEP
2213 select MFD_CORE
2214 ---help---
2215 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2217 config OLPC_XO1_RTC
2218 bool "OLPC XO-1 Real Time Clock"
2219 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2220 ---help---
2221 Add support for the XO-1 real time clock, which can be used as a
2222 programmable wakeup source.
2224 config OLPC_XO1_SCI
2225 bool "OLPC XO-1 SCI extras"
2226 depends on OLPC && OLPC_XO1_PM
2227 depends on INPUT=y
2228 select POWER_SUPPLY
2229 select GPIO_CS5535
2230 select MFD_CORE
2231 ---help---
2232 Add support for SCI-based features of the OLPC XO-1 laptop:
2233 - EC-driven system wakeups
2234 - Power button
2235 - Ebook switch
2236 - Lid switch
2237 - AC adapter status updates
2238 - Battery status updates
2240 config OLPC_XO15_SCI
2241 bool "OLPC XO-1.5 SCI extras"
2242 depends on OLPC && ACPI
2243 select POWER_SUPPLY
2244 ---help---
2245 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2246 - EC-driven system wakeups
2247 - AC adapter status updates
2248 - Battery status updates
2250 config ALIX
2251 bool "PCEngines ALIX System Support (LED setup)"
2252 select GPIOLIB
2253 ---help---
2254 This option enables system support for the PCEngines ALIX.
2255 At present this just sets up LEDs for GPIO control on
2256 ALIX2/3/6 boards. However, other system specific setup should
2257 get added here.
2259 Note: You must still enable the drivers for GPIO and LED support
2260 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2262 Note: You have to set alix.force=1 for boards with Award BIOS.
2264 config NET5501
2265 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2266 select GPIOLIB
2267 ---help---
2268 This option enables system support for the Soekris Engineering net5501.
2270 config GEOS
2271 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2272 select GPIOLIB
2273 depends on DMI
2274 ---help---
2275 This option enables system support for the Traverse Technologies GEOS.
2277 config TS5500
2278 bool "Technologic Systems TS-5500 platform support"
2279 depends on MELAN
2280 select CHECK_SIGNATURE
2281 select NEW_LEDS
2282 select LEDS_CLASS
2283 ---help---
2284 This option enables system support for the Technologic Systems TS-5500.
2286 endif # X86_32
2288 config AMD_NB
2289 def_bool y
2290 depends on CPU_SUP_AMD && PCI
2292 source "drivers/pcmcia/Kconfig"
2294 source "drivers/pci/hotplug/Kconfig"
2296 config RAPIDIO
2297 tristate "RapidIO support"
2298 depends on PCI
2299 default n
2300 help
2301 If enabled this option will include drivers and the core
2302 infrastructure code to support RapidIO interconnect devices.
2304 source "drivers/rapidio/Kconfig"
2306 config X86_SYSFB
2307 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2308 help
2309 Firmwares often provide initial graphics framebuffers so the BIOS,
2310 bootloader or kernel can show basic video-output during boot for
2311 user-guidance and debugging. Historically, x86 used the VESA BIOS
2312 Extensions and EFI-framebuffers for this, which are mostly limited
2313 to x86.
2314 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2315 framebuffers so the new generic system-framebuffer drivers can be
2316 used on x86. If the framebuffer is not compatible with the generic
2317 modes, it is adverticed as fallback platform framebuffer so legacy
2318 drivers like efifb, vesafb and uvesafb can pick it up.
2319 If this option is not selected, all system framebuffers are always
2320 marked as fallback platform framebuffers as usual.
2322 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2323 not be able to pick up generic system framebuffers if this option
2324 is selected. You are highly encouraged to enable simplefb as
2325 replacement if you select this option. simplefb can correctly deal
2326 with generic system framebuffers. But you should still keep vesafb
2327 and others enabled as fallback if a system framebuffer is
2328 incompatible with simplefb.
2330 If unsure, say Y.
2332 endmenu
2335 menu "Executable file formats / Emulations"
2337 source "fs/Kconfig.binfmt"
2339 config IA32_EMULATION
2340 bool "IA32 Emulation"
2341 depends on X86_64
2342 select BINFMT_ELF
2343 select COMPAT_BINFMT_ELF
2344 select HAVE_UID16
2345 ---help---
2346 Include code to run legacy 32-bit programs under a
2347 64-bit kernel. You should likely turn this on, unless you're
2348 100% sure that you don't have any 32-bit programs left.
2350 config IA32_AOUT
2351 tristate "IA32 a.out support"
2352 depends on IA32_EMULATION
2353 ---help---
2354 Support old a.out binaries in the 32bit emulation.
2356 config X86_X32
2357 bool "x32 ABI for 64-bit mode"
2358 depends on X86_64 && IA32_EMULATION
2359 ---help---
2360 Include code to run binaries for the x32 native 32-bit ABI
2361 for 64-bit processors. An x32 process gets access to the
2362 full 64-bit register file and wide data path while leaving
2363 pointers at 32 bits for smaller memory footprint.
2365 You will need a recent binutils (2.22 or later) with
2366 elf32_x86_64 support enabled to compile a kernel with this
2367 option set.
2369 config COMPAT
2370 def_bool y
2371 depends on IA32_EMULATION || X86_X32
2372 select ARCH_WANT_OLD_COMPAT_IPC
2374 if COMPAT
2375 config COMPAT_FOR_U64_ALIGNMENT
2376 def_bool y
2378 config SYSVIPC_COMPAT
2379 def_bool y
2380 depends on SYSVIPC
2382 config KEYS_COMPAT
2383 def_bool y
2384 depends on KEYS
2385 endif
2387 endmenu
2390 config HAVE_ATOMIC_IOMAP
2391 def_bool y
2392 depends on X86_32
2394 config X86_DEV_DMA_OPS
2395 bool
2396 depends on X86_64 || STA2X11
2398 config X86_DMA_REMAP
2399 bool
2400 depends on STA2X11
2402 config IOSF_MBI
2403 tristate
2404 default m
2405 depends on PCI
2407 source "net/Kconfig"
2409 source "drivers/Kconfig"
2411 source "drivers/firmware/Kconfig"
2413 source "fs/Kconfig"
2415 source "arch/x86/Kconfig.debug"
2417 source "security/Kconfig"
2419 source "crypto/Kconfig"
2421 source "arch/x86/kvm/Kconfig"
2423 source "lib/Kconfig"