| blob | 25d2c6f7325e8d64133100d651661af713f6563a |
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH != "i386"
5 ---help---
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
9 config X86_32
10 def_bool y
11 depends on !64BIT
12 select CLKSRC_I8253
13 select HAVE_UID16
15 config X86_64
16 def_bool y
17 depends on 64BIT
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
21 ### Arch settings
22 config X86
23 def_bool y
24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
25 select ARCH_MIGHT_HAVE_PC_PARPORT
26 select ARCH_MIGHT_HAVE_PC_SERIO
27 select HAVE_AOUT if X86_32
28 select HAVE_UNSTABLE_SCHED_CLOCK
29 select ARCH_SUPPORTS_NUMA_BALANCING
30 select ARCH_SUPPORTS_INT128 if X86_64
31 select ARCH_WANTS_PROT_NUMA_PROT_NONE
32 select HAVE_IDE
33 select HAVE_OPROFILE
34 select HAVE_PCSPKR_PLATFORM
35 select HAVE_PERF_EVENTS
36 select HAVE_IOREMAP_PROT
37 select HAVE_KPROBES
38 select HAVE_MEMBLOCK
39 select HAVE_MEMBLOCK_NODE_MAP
40 select ARCH_DISCARD_MEMBLOCK
41 select ARCH_WANT_OPTIONAL_GPIOLIB
42 select ARCH_WANT_FRAME_POINTERS
43 select HAVE_DMA_ATTRS
44 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
45 select HAVE_KRETPROBES
46 select GENERIC_EARLY_IOREMAP
47 select HAVE_OPTPROBES
48 select HAVE_KPROBES_ON_FTRACE
49 select HAVE_FTRACE_MCOUNT_RECORD
50 select HAVE_FENTRY if X86_64
51 select HAVE_C_RECORDMCOUNT
52 select HAVE_DYNAMIC_FTRACE
53 select HAVE_DYNAMIC_FTRACE_WITH_REGS
54 select HAVE_FUNCTION_TRACER
55 select HAVE_FUNCTION_GRAPH_TRACER
56 select HAVE_FUNCTION_GRAPH_FP_TEST
57 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
58 select HAVE_SYSCALL_TRACEPOINTS
59 select SYSCTL_EXCEPTION_TRACE
60 select HAVE_KVM
61 select HAVE_ARCH_KGDB
62 select HAVE_ARCH_TRACEHOOK
63 select HAVE_GENERIC_DMA_COHERENT if X86_32
64 select HAVE_EFFICIENT_UNALIGNED_ACCESS
65 select USER_STACKTRACE_SUPPORT
66 select HAVE_REGS_AND_STACK_ACCESS_API
67 select HAVE_DMA_API_DEBUG
68 select HAVE_KERNEL_GZIP
69 select HAVE_KERNEL_BZIP2
70 select HAVE_KERNEL_LZMA
71 select HAVE_KERNEL_XZ
72 select HAVE_KERNEL_LZO
73 select HAVE_KERNEL_LZ4
74 select HAVE_HW_BREAKPOINT
75 select HAVE_MIXED_BREAKPOINTS_REGS
76 select PERF_EVENTS
77 select HAVE_PERF_EVENTS_NMI
78 select HAVE_PERF_REGS
79 select HAVE_PERF_USER_STACK_DUMP
80 select HAVE_DEBUG_KMEMLEAK
81 select ANON_INODES
82 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
83 select HAVE_CMPXCHG_LOCAL
84 select HAVE_CMPXCHG_DOUBLE
85 select HAVE_ARCH_KMEMCHECK
86 select HAVE_USER_RETURN_NOTIFIER
87 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
88 select HAVE_ARCH_JUMP_LABEL
89 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90 select SPARSE_IRQ
91 select GENERIC_FIND_FIRST_BIT
92 select GENERIC_IRQ_PROBE
93 select GENERIC_PENDING_IRQ if SMP
94 select GENERIC_IRQ_SHOW
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select IRQ_FORCED_THREADING
97 select HAVE_BPF_JIT if X86_64
98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select CLKEVT_I8253
100 select ARCH_HAVE_NMI_SAFE_CMPXCHG
101 select GENERIC_IOMAP
102 select DCACHE_WORD_ACCESS
103 select GENERIC_SMP_IDLE_THREAD
104 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
105 select HAVE_ARCH_SECCOMP_FILTER
106 select BUILDTIME_EXTABLE_SORT
107 select GENERIC_CMOS_UPDATE
108 select HAVE_ARCH_SOFT_DIRTY
109 select CLOCKSOURCE_WATCHDOG
110 select GENERIC_CLOCKEVENTS
111 select ARCH_CLOCKSOURCE_DATA
112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113 select GENERIC_TIME_VSYSCALL
114 select KTIME_SCALAR if X86_32
115 select GENERIC_STRNCPY_FROM_USER
116 select GENERIC_STRNLEN_USER
117 select HAVE_CONTEXT_TRACKING if X86_64
118 select HAVE_IRQ_TIME_ACCOUNTING
119 select VIRT_TO_BUS
120 select MODULES_USE_ELF_REL if X86_32
121 select MODULES_USE_ELF_RELA if X86_64
122 select CLONE_BACKWARDS if X86_32
123 select ARCH_USE_BUILTIN_BSWAP
124 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
125 select OLD_SIGACTION if X86_32
126 select COMPAT_OLD_SIGACTION if IA32_EMULATION
127 select RTC_LIB
128 select HAVE_DEBUG_STACKOVERFLOW
129 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
130 select HAVE_CC_STACKPROTECTOR
131 select GENERIC_CPU_AUTOPROBE
132 select HAVE_ARCH_AUDITSYSCALL
134 config INSTRUCTION_DECODER
135 def_bool y
136 depends on KPROBES || PERF_EVENTS || UPROBES
138 config OUTPUT_FORMAT
139 string
140 default "elf32-i386" if X86_32
141 default "elf64-x86-64" if X86_64
143 config ARCH_DEFCONFIG
144 string
145 default "arch/x86/configs/i386_defconfig" if X86_32
146 default "arch/x86/configs/x86_64_defconfig" if X86_64
148 config LOCKDEP_SUPPORT
149 def_bool y
151 config STACKTRACE_SUPPORT
152 def_bool y
154 config HAVE_LATENCYTOP_SUPPORT
155 def_bool y
157 config MMU
158 def_bool y
160 config SBUS
161 bool
163 config NEED_DMA_MAP_STATE
164 def_bool y
165 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
167 config NEED_SG_DMA_LENGTH
168 def_bool y
170 config GENERIC_ISA_DMA
171 def_bool y
172 depends on ISA_DMA_API
174 config GENERIC_BUG
175 def_bool y
176 depends on BUG
177 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
179 config GENERIC_BUG_RELATIVE_POINTERS
180 bool
182 config GENERIC_HWEIGHT
183 def_bool y
185 config ARCH_MAY_HAVE_PC_FDC
186 def_bool y
187 depends on ISA_DMA_API
189 config RWSEM_XCHGADD_ALGORITHM
190 def_bool y
192 config GENERIC_CALIBRATE_DELAY
193 def_bool y
195 config ARCH_HAS_CPU_RELAX
196 def_bool y
198 config ARCH_HAS_CACHE_LINE_SIZE
199 def_bool y
201 config HAVE_SETUP_PER_CPU_AREA
202 def_bool y
204 config NEED_PER_CPU_EMBED_FIRST_CHUNK
205 def_bool y
207 config NEED_PER_CPU_PAGE_FIRST_CHUNK
208 def_bool y
210 config ARCH_HIBERNATION_POSSIBLE
211 def_bool y
213 config ARCH_SUSPEND_POSSIBLE
214 def_bool y
216 config ARCH_WANT_HUGE_PMD_SHARE
217 def_bool y
219 config ARCH_WANT_GENERAL_HUGETLB
220 def_bool y
222 config ZONE_DMA32
223 bool
224 default X86_64
226 config AUDIT_ARCH
227 bool
228 default X86_64
230 config ARCH_SUPPORTS_OPTIMIZED_INLINING
231 def_bool y
233 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
234 def_bool y
236 config HAVE_INTEL_TXT
237 def_bool y
238 depends on INTEL_IOMMU && ACPI
240 config X86_32_SMP
241 def_bool y
242 depends on X86_32 && SMP
244 config X86_64_SMP
245 def_bool y
246 depends on X86_64 && SMP
248 config X86_HT
249 def_bool y
250 depends on SMP
252 config X86_32_LAZY_GS
253 def_bool y
254 depends on X86_32 && !CC_STACKPROTECTOR
256 config ARCH_HWEIGHT_CFLAGS
257 string
258 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
259 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
261 config ARCH_SUPPORTS_UPROBES
262 def_bool y
264 source "init/Kconfig"
265 source "kernel/Kconfig.freezer"
267 menu "Processor type and features"
269 config ZONE_DMA
270 bool "DMA memory allocation support" if EXPERT
271 default y
272 help
273 DMA memory allocation support allows devices with less than 32-bit
274 addressing to allocate within the first 16MB of address space.
275 Disable if no such devices will be used.
277 If unsure, say Y.
279 config SMP
280 bool "Symmetric multi-processing support"
281 ---help---
282 This enables support for systems with more than one CPU. If you have
283 a system with only one CPU, say N. If you have a system with more
284 than one CPU, say Y.
286 If you say N here, the kernel will run on uni- and multiprocessor
287 machines, but will use only one CPU of a multiprocessor machine. If
288 you say Y here, the kernel will run on many, but not all,
289 uniprocessor machines. On a uniprocessor machine, the kernel
290 will run faster if you say N here.
292 Note that if you say Y here and choose architecture "586" or
293 "Pentium" under "Processor family", the kernel will not work on 486
294 architectures. Similarly, multiprocessor kernels for the "PPro"
295 architecture may not work on all Pentium based boards.
297 People using multiprocessor machines who say Y here should also say
298 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
299 Management" code will be disabled if you say Y here.
301 See also <file:Documentation/x86/i386/IO-APIC.txt>,
302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
303 <http://www.tldp.org/docs.html#howto>.
305 If you don't know what to do here, say N.
307 config X86_X2APIC
308 bool "Support x2apic"
309 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
310 ---help---
311 This enables x2apic support on CPUs that have this feature.
313 This allows 32-bit apic IDs (so it can support very large systems),
314 and accesses the local apic via MSRs not via mmio.
316 If you don't know what to do here, say N.
318 config X86_MPPARSE
319 bool "Enable MPS table" if ACPI || SFI
320 default y
321 depends on X86_LOCAL_APIC
322 ---help---
323 For old smp systems that do not have proper acpi support. Newer systems
324 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
326 config X86_BIGSMP
327 bool "Support for big SMP systems with more than 8 CPUs"
328 depends on X86_32 && SMP
329 ---help---
330 This option is needed for the systems that have more than 8 CPUs
332 config GOLDFISH
333 def_bool y
334 depends on X86_GOLDFISH
336 if X86_32
337 config X86_EXTENDED_PLATFORM
338 bool "Support for extended (non-PC) x86 platforms"
339 default y
340 ---help---
341 If you disable this option then the kernel will only support
342 standard PC platforms. (which covers the vast majority of
343 systems out there.)
345 If you enable this option then you'll be able to select support
346 for the following (non-PC) 32 bit x86 platforms:
347 Goldfish (Android emulator)
348 AMD Elan
349 RDC R-321x SoC
350 SGI 320/540 (Visual Workstation)
351 STA2X11-based (e.g. Northville)
352 Moorestown MID devices
354 If you have one of these systems, or if you want to build a
355 generic distribution kernel, say Y here - otherwise say N.
356 endif
358 if X86_64
359 config X86_EXTENDED_PLATFORM
360 bool "Support for extended (non-PC) x86 platforms"
361 default y
362 ---help---
363 If you disable this option then the kernel will only support
364 standard PC platforms. (which covers the vast majority of
365 systems out there.)
367 If you enable this option then you'll be able to select support
368 for the following (non-PC) 64 bit x86 platforms:
369 Numascale NumaChip
370 ScaleMP vSMP
371 SGI Ultraviolet
373 If you have one of these systems, or if you want to build a
374 generic distribution kernel, say Y here - otherwise say N.
375 endif
376 # This is an alphabetically sorted list of 64 bit extended platforms
377 # Please maintain the alphabetic order if and when there are additions
378 config X86_NUMACHIP
379 bool "Numascale NumaChip"
380 depends on X86_64
381 depends on X86_EXTENDED_PLATFORM
382 depends on NUMA
383 depends on SMP
384 depends on X86_X2APIC
385 depends on PCI_MMCONFIG
386 ---help---
387 Adds support for Numascale NumaChip large-SMP systems. Needed to
388 enable more than ~168 cores.
389 If you don't have one of these, you should say N here.
391 config X86_VSMP
392 bool "ScaleMP vSMP"
393 select HYPERVISOR_GUEST
394 select PARAVIRT
395 depends on X86_64 && PCI
396 depends on X86_EXTENDED_PLATFORM
397 depends on SMP
398 ---help---
399 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
400 supposed to run on these EM64T-based machines. Only choose this option
401 if you have one of these machines.
403 config X86_UV
404 bool "SGI Ultraviolet"
405 depends on X86_64
406 depends on X86_EXTENDED_PLATFORM
407 depends on NUMA
408 depends on X86_X2APIC
409 ---help---
410 This option is needed in order to support SGI Ultraviolet systems.
411 If you don't have one of these, you should say N here.
413 # Following is an alphabetically sorted list of 32 bit extended platforms
414 # Please maintain the alphabetic order if and when there are additions
416 config X86_GOLDFISH
417 bool "Goldfish (Virtual Platform)"
418 depends on X86_32
419 depends on X86_EXTENDED_PLATFORM
420 ---help---
421 Enable support for the Goldfish virtual platform used primarily
422 for Android development. Unless you are building for the Android
423 Goldfish emulator say N here.
425 config X86_INTEL_CE
426 bool "CE4100 TV platform"
427 depends on PCI
428 depends on PCI_GODIRECT
429 depends on X86_32
430 depends on X86_EXTENDED_PLATFORM
431 select X86_REBOOTFIXUPS
432 select OF
433 select OF_EARLY_FLATTREE
434 select IRQ_DOMAIN
435 ---help---
436 Select for the Intel CE media processor (CE4100) SOC.
437 This option compiles in support for the CE4100 SOC for settop
438 boxes and media devices.
440 config X86_INTEL_MID
441 bool "Intel MID platform support"
442 depends on X86_32
443 depends on X86_EXTENDED_PLATFORM
444 depends on X86_PLATFORM_DEVICES
445 depends on PCI
446 depends on PCI_GOANY
447 depends on X86_IO_APIC
448 select SFI
449 select I2C
450 select DW_APB_TIMER
451 select APB_TIMER
452 select INTEL_SCU_IPC
453 select MFD_INTEL_MSIC
454 ---help---
455 Select to build a kernel capable of supporting Intel MID (Mobile
456 Internet Device) platform systems which do not have the PCI legacy
457 interfaces. If you are building for a PC class system say N here.
459 Intel MID platforms are based on an Intel processor and chipset which
460 consume less power than most of the x86 derivatives.
462 config X86_INTEL_LPSS
463 bool "Intel Low Power Subsystem Support"
464 depends on ACPI
465 select COMMON_CLK
466 select PINCTRL
467 ---help---
468 Select to build support for Intel Low Power Subsystem such as
469 found on Intel Lynxpoint PCH. Selecting this option enables
470 things like clock tree (common clock framework) and pincontrol
471 which are needed by the LPSS peripheral drivers.
473 config X86_RDC321X
474 bool "RDC R-321x SoC"
475 depends on X86_32
476 depends on X86_EXTENDED_PLATFORM
477 select M486
478 select X86_REBOOTFIXUPS
479 ---help---
480 This option is needed for RDC R-321x system-on-chip, also known
481 as R-8610-(G).
482 If you don't have one of these chips, you should say N here.
484 config X86_32_NON_STANDARD
485 bool "Support non-standard 32-bit SMP architectures"
486 depends on X86_32 && SMP
487 depends on X86_EXTENDED_PLATFORM
488 ---help---
489 This option compiles in the bigsmp and STA2X11 default
490 subarchitectures. It is intended for a generic binary
491 kernel. If you select them all, kernel will probe it one by
492 one and will fallback to default.
494 # Alphabetically sorted list of Non standard 32 bit platforms
496 config X86_SUPPORTS_MEMORY_FAILURE
497 def_bool y
498 # MCE code calls memory_failure():
499 depends on X86_MCE
500 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
501 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
502 depends on X86_64 || !SPARSEMEM
503 select ARCH_SUPPORTS_MEMORY_FAILURE
505 config STA2X11
506 bool "STA2X11 Companion Chip Support"
507 depends on X86_32_NON_STANDARD && PCI
508 select X86_DEV_DMA_OPS
509 select X86_DMA_REMAP
510 select SWIOTLB
511 select MFD_STA2X11
512 select ARCH_REQUIRE_GPIOLIB
513 default n
514 ---help---
515 This adds support for boards based on the STA2X11 IO-Hub,
516 a.k.a. "ConneXt". The chip is used in place of the standard
517 PC chipset, so all "standard" peripherals are missing. If this
518 option is selected the kernel will still be able to boot on
519 standard PC machines.
521 config X86_32_IRIS
522 tristate "Eurobraille/Iris poweroff module"
523 depends on X86_32
524 ---help---
525 The Iris machines from EuroBraille do not have APM or ACPI support
526 to shut themselves down properly. A special I/O sequence is
527 needed to do so, which is what this module does at
528 kernel shutdown.
530 This is only for Iris machines from EuroBraille.
532 If unused, say N.
534 config SCHED_OMIT_FRAME_POINTER
535 def_bool y
536 prompt "Single-depth WCHAN output"
537 depends on X86
538 ---help---
539 Calculate simpler /proc/<PID>/wchan values. If this option
540 is disabled then wchan values will recurse back to the
541 caller function. This provides more accurate wchan values,
542 at the expense of slightly more scheduling overhead.
544 If in doubt, say "Y".
546 menuconfig HYPERVISOR_GUEST
547 bool "Linux guest support"
548 ---help---
549 Say Y here to enable options for running Linux under various hyper-
550 visors. This option enables basic hypervisor detection and platform
551 setup.
553 If you say N, all options in this submenu will be skipped and
554 disabled, and Linux guest support won't be built in.
556 if HYPERVISOR_GUEST
558 config PARAVIRT
559 bool "Enable paravirtualization code"
560 ---help---
561 This changes the kernel so it can modify itself when it is run
562 under a hypervisor, potentially improving performance significantly
563 over full virtualization. However, when run without a hypervisor
564 the kernel is theoretically slower and slightly larger.
566 config PARAVIRT_DEBUG
567 bool "paravirt-ops debugging"
568 depends on PARAVIRT && DEBUG_KERNEL
569 ---help---
570 Enable to debug paravirt_ops internals. Specifically, BUG if
571 a paravirt_op is missing when it is called.
573 config PARAVIRT_SPINLOCKS
574 bool "Paravirtualization layer for spinlocks"
575 depends on PARAVIRT && SMP
576 select UNINLINE_SPIN_UNLOCK
577 ---help---
578 Paravirtualized spinlocks allow a pvops backend to replace the
579 spinlock implementation with something virtualization-friendly
580 (for example, block the virtual CPU rather than spinning).
582 It has a minimal impact on native kernels and gives a nice performance
583 benefit on paravirtualized KVM / Xen kernels.
585 If you are unsure how to answer this question, answer Y.
587 source "arch/x86/xen/Kconfig"
589 config KVM_GUEST
590 bool "KVM Guest support (including kvmclock)"
591 depends on PARAVIRT
592 select PARAVIRT_CLOCK
593 default y
594 ---help---
595 This option enables various optimizations for running under the KVM
596 hypervisor. It includes a paravirtualized clock, so that instead
597 of relying on a PIT (or probably other) emulation by the
598 underlying device model, the host provides the guest with
599 timing infrastructure such as time of day, and system time
601 config KVM_DEBUG_FS
602 bool "Enable debug information for KVM Guests in debugfs"
603 depends on KVM_GUEST && DEBUG_FS
604 default n
605 ---help---
606 This option enables collection of various statistics for KVM guest.
607 Statistics are displayed in debugfs filesystem. Enabling this option
608 may incur significant overhead.
610 source "arch/x86/lguest/Kconfig"
612 config PARAVIRT_TIME_ACCOUNTING
613 bool "Paravirtual steal time accounting"
614 depends on PARAVIRT
615 default n
616 ---help---
617 Select this option to enable fine granularity task steal time
618 accounting. Time spent executing other tasks in parallel with
619 the current vCPU is discounted from the vCPU power. To account for
620 that, there can be a small performance impact.
622 If in doubt, say N here.
624 config PARAVIRT_CLOCK
625 bool
627 endif #HYPERVISOR_GUEST
629 config NO_BOOTMEM
630 def_bool y
632 config MEMTEST
633 bool "Memtest"
634 ---help---
635 This option adds a kernel parameter 'memtest', which allows memtest
636 to be set.
637 memtest=0, mean disabled; -- default
638 memtest=1, mean do 1 test pattern;
639 ...
640 memtest=4, mean do 4 test patterns.
641 If you are unsure how to answer this question, answer N.
643 source "arch/x86/Kconfig.cpu"
645 config HPET_TIMER
646 def_bool X86_64
647 prompt "HPET Timer Support" if X86_32
648 ---help---
649 Use the IA-PC HPET (High Precision Event Timer) to manage
650 time in preference to the PIT and RTC, if a HPET is
651 present.
652 HPET is the next generation timer replacing legacy 8254s.
653 The HPET provides a stable time base on SMP
654 systems, unlike the TSC, but it is more expensive to access,
655 as it is off-chip. You can find the HPET spec at
656 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
658 You can safely choose Y here. However, HPET will only be
659 activated if the platform and the BIOS support this feature.
660 Otherwise the 8254 will be used for timing services.
662 Choose N to continue using the legacy 8254 timer.
664 config HPET_EMULATE_RTC
665 def_bool y
666 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
668 config APB_TIMER
669 def_bool y if X86_INTEL_MID
670 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
671 select DW_APB_TIMER
672 depends on X86_INTEL_MID && SFI
673 help
674 APB timer is the replacement for 8254, HPET on X86 MID platforms.
675 The APBT provides a stable time base on SMP
676 systems, unlike the TSC, but it is more expensive to access,
677 as it is off-chip. APB timers are always running regardless of CPU
678 C states, they are used as per CPU clockevent device when possible.
680 # Mark as expert because too many people got it wrong.
681 # The code disables itself when not needed.
682 config DMI
683 default y
684 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
685 bool "Enable DMI scanning" if EXPERT
686 ---help---
687 Enabled scanning of DMI to identify machine quirks. Say Y
688 here unless you have verified that your setup is not
689 affected by entries in the DMI blacklist. Required by PNP
690 BIOS code.
692 config GART_IOMMU
693 bool "Old AMD GART IOMMU support"
694 select SWIOTLB
695 depends on X86_64 && PCI && AMD_NB
696 ---help---
697 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
698 GART based hardware IOMMUs.
700 The GART supports full DMA access for devices with 32-bit access
701 limitations, on systems with more than 3 GB. This is usually needed
702 for USB, sound, many IDE/SATA chipsets and some other devices.
704 Newer systems typically have a modern AMD IOMMU, supported via
705 the CONFIG_AMD_IOMMU=y config option.
707 In normal configurations this driver is only active when needed:
708 there's more than 3 GB of memory and the system contains a
709 32-bit limited device.
711 If unsure, say Y.
713 config CALGARY_IOMMU
714 bool "IBM Calgary IOMMU support"
715 select SWIOTLB
716 depends on X86_64 && PCI
717 ---help---
718 Support for hardware IOMMUs in IBM's xSeries x366 and x460
719 systems. Needed to run systems with more than 3GB of memory
720 properly with 32-bit PCI devices that do not support DAC
721 (Double Address Cycle). Calgary also supports bus level
722 isolation, where all DMAs pass through the IOMMU. This
723 prevents them from going anywhere except their intended
724 destination. This catches hard-to-find kernel bugs and
725 mis-behaving drivers and devices that do not use the DMA-API
726 properly to set up their DMA buffers. The IOMMU can be
727 turned off at boot time with the iommu=off parameter.
728 Normally the kernel will make the right choice by itself.
729 If unsure, say Y.
731 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
732 def_bool y
733 prompt "Should Calgary be enabled by default?"
734 depends on CALGARY_IOMMU
735 ---help---
736 Should Calgary be enabled by default? if you choose 'y', Calgary
737 will be used (if it exists). If you choose 'n', Calgary will not be
738 used even if it exists. If you choose 'n' and would like to use
739 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
740 If unsure, say Y.
742 # need this always selected by IOMMU for the VIA workaround
743 config SWIOTLB
744 def_bool y if X86_64
745 ---help---
746 Support for software bounce buffers used on x86-64 systems
747 which don't have a hardware IOMMU. Using this PCI devices
748 which can only access 32-bits of memory can be used on systems
749 with more than 3 GB of memory.
750 If unsure, say Y.
752 config IOMMU_HELPER
753 def_bool y
754 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
756 config MAXSMP
757 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
758 depends on X86_64 && SMP && DEBUG_KERNEL
759 select CPUMASK_OFFSTACK
760 ---help---
761 Enable maximum number of CPUS and NUMA Nodes for this architecture.
762 If unsure, say N.
764 config NR_CPUS
765 int "Maximum number of CPUs" if SMP && !MAXSMP
766 range 2 8 if SMP && X86_32 && !X86_BIGSMP
767 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
768 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
769 default "1" if !SMP
770 default "8192" if MAXSMP
771 default "32" if SMP && X86_BIGSMP
772 default "8" if SMP
773 ---help---
774 This allows you to specify the maximum number of CPUs which this
775 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
776 supported value is 4096, otherwise the maximum value is 512. The
777 minimum value which makes sense is 2.
779 This is purely to save memory - each supported CPU adds
780 approximately eight kilobytes to the kernel image.
782 config SCHED_SMT
783 bool "SMT (Hyperthreading) scheduler support"
784 depends on X86_HT
785 ---help---
786 SMT scheduler support improves the CPU scheduler's decision making
787 when dealing with Intel Pentium 4 chips with HyperThreading at a
788 cost of slightly increased overhead in some places. If unsure say
789 N here.
791 config SCHED_MC
792 def_bool y
793 prompt "Multi-core scheduler support"
794 depends on X86_HT
795 ---help---
796 Multi-core scheduler support improves the CPU scheduler's decision
797 making when dealing with multi-core CPU chips at a cost of slightly
798 increased overhead in some places. If unsure say N here.
800 source "kernel/Kconfig.preempt"
802 config X86_UP_APIC
803 bool "Local APIC support on uniprocessors"
804 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
805 ---help---
806 A local APIC (Advanced Programmable Interrupt Controller) is an
807 integrated interrupt controller in the CPU. If you have a single-CPU
808 system which has a processor with a local APIC, you can say Y here to
809 enable and use it. If you say Y here even though your machine doesn't
810 have a local APIC, then the kernel will still run with no slowdown at
811 all. The local APIC supports CPU-generated self-interrupts (timer,
812 performance counters), and the NMI watchdog which detects hard
813 lockups.
815 config X86_UP_IOAPIC
816 bool "IO-APIC support on uniprocessors"
817 depends on X86_UP_APIC
818 ---help---
819 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
820 SMP-capable replacement for PC-style interrupt controllers. Most
821 SMP systems and many recent uniprocessor systems have one.
823 If you have a single-CPU system with an IO-APIC, you can say Y here
824 to use it. If you say Y here even though your machine doesn't have
825 an IO-APIC, then the kernel will still run with no slowdown at all.
827 config X86_LOCAL_APIC
828 def_bool y
829 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
831 config X86_IO_APIC
832 def_bool y
833 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
835 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
836 bool "Reroute for broken boot IRQs"
837 depends on X86_IO_APIC
838 ---help---
839 This option enables a workaround that fixes a source of
840 spurious interrupts. This is recommended when threaded
841 interrupt handling is used on systems where the generation of
842 superfluous "boot interrupts" cannot be disabled.
844 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
845 entry in the chipset's IO-APIC is masked (as, e.g. the RT
846 kernel does during interrupt handling). On chipsets where this
847 boot IRQ generation cannot be disabled, this workaround keeps
848 the original IRQ line masked so that only the equivalent "boot
849 IRQ" is delivered to the CPUs. The workaround also tells the
850 kernel to set up the IRQ handler on the boot IRQ line. In this
851 way only one interrupt is delivered to the kernel. Otherwise
852 the spurious second interrupt may cause the kernel to bring
853 down (vital) interrupt lines.
855 Only affects "broken" chipsets. Interrupt sharing may be
856 increased on these systems.
858 config X86_MCE
859 bool "Machine Check / overheating reporting"
860 default y
861 ---help---
862 Machine Check support allows the processor to notify the
863 kernel if it detects a problem (e.g. overheating, data corruption).
864 The action the kernel takes depends on the severity of the problem,
865 ranging from warning messages to halting the machine.
867 config X86_MCE_INTEL
868 def_bool y
869 prompt "Intel MCE features"
870 depends on X86_MCE && X86_LOCAL_APIC
871 ---help---
872 Additional support for intel specific MCE features such as
873 the thermal monitor.
875 config X86_MCE_AMD
876 def_bool y
877 prompt "AMD MCE features"
878 depends on X86_MCE && X86_LOCAL_APIC
879 ---help---
880 Additional support for AMD specific MCE features such as
881 the DRAM Error Threshold.
883 config X86_ANCIENT_MCE
884 bool "Support for old Pentium 5 / WinChip machine checks"
885 depends on X86_32 && X86_MCE
886 ---help---
887 Include support for machine check handling on old Pentium 5 or WinChip
888 systems. These typically need to be enabled explicitly on the command
889 line.
891 config X86_MCE_THRESHOLD
892 depends on X86_MCE_AMD || X86_MCE_INTEL
893 def_bool y
895 config X86_MCE_INJECT
896 depends on X86_MCE
897 tristate "Machine check injector support"
898 ---help---
899 Provide support for injecting machine checks for testing purposes.
900 If you don't know what a machine check is and you don't do kernel
901 QA it is safe to say n.
903 config X86_THERMAL_VECTOR
904 def_bool y
905 depends on X86_MCE_INTEL
907 config VM86
908 bool "Enable VM86 support" if EXPERT
909 default y
910 depends on X86_32
911 ---help---
912 This option is required by programs like DOSEMU to run 16-bit legacy
913 code on X86 processors. It also may be needed by software like
914 XFree86 to initialize some video cards via BIOS. Disabling this
915 option saves about 6k.
917 config TOSHIBA
918 tristate "Toshiba Laptop support"
919 depends on X86_32
920 ---help---
921 This adds a driver to safely access the System Management Mode of
922 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
923 not work on models with a Phoenix BIOS. The System Management Mode
924 is used to set the BIOS and power saving options on Toshiba portables.
926 For information on utilities to make use of this driver see the
927 Toshiba Linux utilities web site at:
928 <http://www.buzzard.org.uk/toshiba/>.
930 Say Y if you intend to run this kernel on a Toshiba portable.
931 Say N otherwise.
933 config I8K
934 tristate "Dell laptop support"
935 select HWMON
936 ---help---
937 This adds a driver to safely access the System Management Mode
938 of the CPU on the Dell Inspiron 8000. The System Management Mode
939 is used to read cpu temperature and cooling fan status and to
940 control the fans on the I8K portables.
942 This driver has been tested only on the Inspiron 8000 but it may
943 also work with other Dell laptops. You can force loading on other
944 models by passing the parameter `force=1' to the module. Use at
945 your own risk.
947 For information on utilities to make use of this driver see the
948 I8K Linux utilities web site at:
949 <http://people.debian.org/~dz/i8k/>
951 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
952 Say N otherwise.
954 config X86_REBOOTFIXUPS
955 bool "Enable X86 board specific fixups for reboot"
956 depends on X86_32
957 ---help---
958 This enables chipset and/or board specific fixups to be done
959 in order to get reboot to work correctly. This is only needed on
960 some combinations of hardware and BIOS. The symptom, for which
961 this config is intended, is when reboot ends with a stalled/hung
962 system.
964 Currently, the only fixup is for the Geode machines using
965 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
967 Say Y if you want to enable the fixup. Currently, it's safe to
968 enable this option even if you don't need it.
969 Say N otherwise.
971 config MICROCODE
972 tristate "CPU microcode loading support"
973 depends on CPU_SUP_AMD || CPU_SUP_INTEL
974 select FW_LOADER
975 ---help---
977 If you say Y here, you will be able to update the microcode on
978 certain Intel and AMD processors. The Intel support is for the
979 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
980 Xeon etc. The AMD support is for families 0x10 and later. You will
981 obviously need the actual microcode binary data itself which is not
982 shipped with the Linux kernel.
984 This option selects the general module only, you need to select
985 at least one vendor specific module as well.
987 To compile this driver as a module, choose M here: the module
988 will be called microcode.
990 config MICROCODE_INTEL
991 bool "Intel microcode loading support"
992 depends on MICROCODE
993 default MICROCODE
994 select FW_LOADER
995 ---help---
996 This options enables microcode patch loading support for Intel
997 processors.
999 For the current Intel microcode data package go to
1000 <https://downloadcenter.intel.com> and search for
1001 'Linux Processor Microcode Data File'.
1003 config MICROCODE_AMD
1004 bool "AMD microcode loading support"
1005 depends on MICROCODE
1006 select FW_LOADER
1007 ---help---
1008 If you select this option, microcode patch loading support for AMD
1009 processors will be enabled.
1011 config MICROCODE_OLD_INTERFACE
1012 def_bool y
1013 depends on MICROCODE
1015 config MICROCODE_INTEL_EARLY
1016 def_bool n
1018 config MICROCODE_AMD_EARLY
1019 def_bool n
1021 config MICROCODE_EARLY
1022 bool "Early load microcode"
1023 depends on MICROCODE=y && BLK_DEV_INITRD
1024 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1025 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1026 default y
1027 help
1028 This option provides functionality to read additional microcode data
1029 at the beginning of initrd image. The data tells kernel to load
1030 microcode to CPU's as early as possible. No functional change if no
1031 microcode data is glued to the initrd, therefore it's safe to say Y.
1033 config X86_MSR
1034 tristate "/dev/cpu/*/msr - Model-specific register support"
1035 ---help---
1036 This device gives privileged processes access to the x86
1037 Model-Specific Registers (MSRs). It is a character device with
1038 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1039 MSR accesses are directed to a specific CPU on multi-processor
1040 systems.
1042 config X86_CPUID
1043 tristate "/dev/cpu/*/cpuid - CPU information support"
1044 ---help---
1045 This device gives processes access to the x86 CPUID instruction to
1046 be executed on a specific processor. It is a character device
1047 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1048 /dev/cpu/31/cpuid.
1050 choice
1051 prompt "High Memory Support"
1052 default HIGHMEM4G
1053 depends on X86_32
1055 config NOHIGHMEM
1056 bool "off"
1057 ---help---
1058 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1059 However, the address space of 32-bit x86 processors is only 4
1060 Gigabytes large. That means that, if you have a large amount of
1061 physical memory, not all of it can be "permanently mapped" by the
1062 kernel. The physical memory that's not permanently mapped is called
1063 "high memory".
1065 If you are compiling a kernel which will never run on a machine with
1066 more than 1 Gigabyte total physical RAM, answer "off" here (default
1067 choice and suitable for most users). This will result in a "3GB/1GB"
1068 split: 3GB are mapped so that each process sees a 3GB virtual memory
1069 space and the remaining part of the 4GB virtual memory space is used
1070 by the kernel to permanently map as much physical memory as
1071 possible.
1073 If the machine has between 1 and 4 Gigabytes physical RAM, then
1074 answer "4GB" here.
1076 If more than 4 Gigabytes is used then answer "64GB" here. This
1077 selection turns Intel PAE (Physical Address Extension) mode on.
1078 PAE implements 3-level paging on IA32 processors. PAE is fully
1079 supported by Linux, PAE mode is implemented on all recent Intel
1080 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1081 then the kernel will not boot on CPUs that don't support PAE!
1083 The actual amount of total physical memory will either be
1084 auto detected or can be forced by using a kernel command line option
1085 such as "mem=256M". (Try "man bootparam" or see the documentation of
1086 your boot loader (lilo or loadlin) about how to pass options to the
1087 kernel at boot time.)
1089 If unsure, say "off".
1091 config HIGHMEM4G
1092 bool "4GB"
1093 ---help---
1094 Select this if you have a 32-bit processor and between 1 and 4
1095 gigabytes of physical RAM.
1097 config HIGHMEM64G
1098 bool "64GB"
1099 depends on !M486
1100 select X86_PAE
1101 ---help---
1102 Select this if you have a 32-bit processor and more than 4
1103 gigabytes of physical RAM.
1105 endchoice
1107 choice
1108 prompt "Memory split" if EXPERT
1109 default VMSPLIT_3G
1110 depends on X86_32
1111 ---help---
1112 Select the desired split between kernel and user memory.
1114 If the address range available to the kernel is less than the
1115 physical memory installed, the remaining memory will be available
1116 as "high memory". Accessing high memory is a little more costly
1117 than low memory, as it needs to be mapped into the kernel first.
1118 Note that increasing the kernel address space limits the range
1119 available to user programs, making the address space there
1120 tighter. Selecting anything other than the default 3G/1G split
1121 will also likely make your kernel incompatible with binary-only
1122 kernel modules.
1124 If you are not absolutely sure what you are doing, leave this
1125 option alone!
1127 config VMSPLIT_3G
1128 bool "3G/1G user/kernel split"
1129 config VMSPLIT_3G_OPT
1130 depends on !X86_PAE
1131 bool "3G/1G user/kernel split (for full 1G low memory)"
1132 config VMSPLIT_2G
1133 bool "2G/2G user/kernel split"
1134 config VMSPLIT_2G_OPT
1135 depends on !X86_PAE
1136 bool "2G/2G user/kernel split (for full 2G low memory)"
1137 config VMSPLIT_1G
1138 bool "1G/3G user/kernel split"
1139 endchoice
1141 config PAGE_OFFSET
1142 hex
1143 default 0xB0000000 if VMSPLIT_3G_OPT
1144 default 0x80000000 if VMSPLIT_2G
1145 default 0x78000000 if VMSPLIT_2G_OPT
1146 default 0x40000000 if VMSPLIT_1G
1147 default 0xC0000000
1148 depends on X86_32
1150 config HIGHMEM
1151 def_bool y
1152 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1154 config X86_PAE
1155 bool "PAE (Physical Address Extension) Support"
1156 depends on X86_32 && !HIGHMEM4G
1157 ---help---
1158 PAE is required for NX support, and furthermore enables
1159 larger swapspace support for non-overcommit purposes. It
1160 has the cost of more pagetable lookup overhead, and also
1161 consumes more pagetable space per process.
1163 config ARCH_PHYS_ADDR_T_64BIT
1164 def_bool y
1165 depends on X86_64 || X86_PAE
1167 config ARCH_DMA_ADDR_T_64BIT
1168 def_bool y
1169 depends on X86_64 || HIGHMEM64G
1171 config DIRECT_GBPAGES
1172 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1173 default y
1174 depends on X86_64
1175 ---help---
1176 Allow the kernel linear mapping to use 1GB pages on CPUs that
1177 support it. This can improve the kernel's performance a tiny bit by
1178 reducing TLB pressure. If in doubt, say "Y".
1180 # Common NUMA Features
1181 config NUMA
1182 bool "Numa Memory Allocation and Scheduler Support"
1183 depends on SMP
1184 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1185 default y if X86_BIGSMP
1186 ---help---
1187 Enable NUMA (Non Uniform Memory Access) support.
1189 The kernel will try to allocate memory used by a CPU on the
1190 local memory controller of the CPU and add some more
1191 NUMA awareness to the kernel.
1193 For 64-bit this is recommended if the system is Intel Core i7
1194 (or later), AMD Opteron, or EM64T NUMA.
1196 For 32-bit this is only needed if you boot a 32-bit
1197 kernel on a 64-bit NUMA platform.
1199 Otherwise, you should say N.
1201 config AMD_NUMA
1202 def_bool y
1203 prompt "Old style AMD Opteron NUMA detection"
1204 depends on X86_64 && NUMA && PCI
1205 ---help---
1206 Enable AMD NUMA node topology detection. You should say Y here if
1207 you have a multi processor AMD system. This uses an old method to
1208 read the NUMA configuration directly from the builtin Northbridge
1209 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1210 which also takes priority if both are compiled in.
1212 config X86_64_ACPI_NUMA
1213 def_bool y
1214 prompt "ACPI NUMA detection"
1215 depends on X86_64 && NUMA && ACPI && PCI
1216 select ACPI_NUMA
1217 ---help---
1218 Enable ACPI SRAT based node topology detection.
1220 # Some NUMA nodes have memory ranges that span
1221 # other nodes. Even though a pfn is valid and
1222 # between a node's start and end pfns, it may not
1223 # reside on that node. See memmap_init_zone()
1224 # for details.
1225 config NODES_SPAN_OTHER_NODES
1226 def_bool y
1227 depends on X86_64_ACPI_NUMA
1229 config NUMA_EMU
1230 bool "NUMA emulation"
1231 depends on NUMA
1232 ---help---
1233 Enable NUMA emulation. A flat machine will be split
1234 into virtual nodes when booted with "numa=fake=N", where N is the
1235 number of nodes. This is only useful for debugging.
1237 config NODES_SHIFT
1238 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1239 range 1 10
1240 default "10" if MAXSMP
1241 default "6" if X86_64
1242 default "3"
1243 depends on NEED_MULTIPLE_NODES
1244 ---help---
1245 Specify the maximum number of NUMA Nodes available on the target
1246 system. Increases memory reserved to accommodate various tables.
1248 config ARCH_HAVE_MEMORY_PRESENT
1249 def_bool y
1250 depends on X86_32 && DISCONTIGMEM
1252 config NEED_NODE_MEMMAP_SIZE
1253 def_bool y
1254 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1256 config ARCH_FLATMEM_ENABLE
1257 def_bool y
1258 depends on X86_32 && !NUMA
1260 config ARCH_DISCONTIGMEM_ENABLE
1261 def_bool y
1262 depends on NUMA && X86_32
1264 config ARCH_DISCONTIGMEM_DEFAULT
1265 def_bool y
1266 depends on NUMA && X86_32
1268 config ARCH_SPARSEMEM_ENABLE
1269 def_bool y
1270 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1271 select SPARSEMEM_STATIC if X86_32
1272 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1274 config ARCH_SPARSEMEM_DEFAULT
1275 def_bool y
1276 depends on X86_64
1278 config ARCH_SELECT_MEMORY_MODEL
1279 def_bool y
1280 depends on ARCH_SPARSEMEM_ENABLE
1282 config ARCH_MEMORY_PROBE
1283 bool "Enable sysfs memory/probe interface"
1284 depends on X86_64 && MEMORY_HOTPLUG
1285 help
1286 This option enables a sysfs memory/probe interface for testing.
1287 See Documentation/memory-hotplug.txt for more information.
1288 If you are unsure how to answer this question, answer N.
1290 config ARCH_PROC_KCORE_TEXT
1291 def_bool y
1292 depends on X86_64 && PROC_KCORE
1294 config ILLEGAL_POINTER_VALUE
1295 hex
1296 default 0 if X86_32
1297 default 0xdead000000000000 if X86_64
1299 source "mm/Kconfig"
1301 config HIGHPTE
1302 bool "Allocate 3rd-level pagetables from highmem"
1303 depends on HIGHMEM
1304 ---help---
1305 The VM uses one page table entry for each page of physical memory.
1306 For systems with a lot of RAM, this can be wasteful of precious
1307 low memory. Setting this option will put user-space page table
1308 entries in high memory.
1310 config X86_CHECK_BIOS_CORRUPTION
1311 bool "Check for low memory corruption"
1312 ---help---
1313 Periodically check for memory corruption in low memory, which
1314 is suspected to be caused by BIOS. Even when enabled in the
1315 configuration, it is disabled at runtime. Enable it by
1316 setting "memory_corruption_check=1" on the kernel command
1317 line. By default it scans the low 64k of memory every 60
1318 seconds; see the memory_corruption_check_size and
1319 memory_corruption_check_period parameters in
1320 Documentation/kernel-parameters.txt to adjust this.
1322 When enabled with the default parameters, this option has
1323 almost no overhead, as it reserves a relatively small amount
1324 of memory and scans it infrequently. It both detects corruption
1325 and prevents it from affecting the running system.
1327 It is, however, intended as a diagnostic tool; if repeatable
1328 BIOS-originated corruption always affects the same memory,
1329 you can use memmap= to prevent the kernel from using that
1330 memory.
1332 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1333 bool "Set the default setting of memory_corruption_check"
1334 depends on X86_CHECK_BIOS_CORRUPTION
1335 default y
1336 ---help---
1337 Set whether the default state of memory_corruption_check is
1338 on or off.
1340 config X86_RESERVE_LOW
1341 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1342 default 64
1343 range 4 640
1344 ---help---
1345 Specify the amount of low memory to reserve for the BIOS.
1347 The first page contains BIOS data structures that the kernel
1348 must not use, so that page must always be reserved.
1350 By default we reserve the first 64K of physical RAM, as a
1351 number of BIOSes are known to corrupt that memory range
1352 during events such as suspend/resume or monitor cable
1353 insertion, so it must not be used by the kernel.
1355 You can set this to 4 if you are absolutely sure that you
1356 trust the BIOS to get all its memory reservations and usages
1357 right. If you know your BIOS have problems beyond the
1358 default 64K area, you can set this to 640 to avoid using the
1359 entire low memory range.
1361 If you have doubts about the BIOS (e.g. suspend/resume does
1362 not work or there's kernel crashes after certain hardware
1363 hotplug events) then you might want to enable
1364 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1365 typical corruption patterns.
1367 Leave this to the default value of 64 if you are unsure.
1369 config MATH_EMULATION
1370 bool
1371 prompt "Math emulation" if X86_32
1372 ---help---
1373 Linux can emulate a math coprocessor (used for floating point
1374 operations) if you don't have one. 486DX and Pentium processors have
1375 a math coprocessor built in, 486SX and 386 do not, unless you added
1376 a 487DX or 387, respectively. (The messages during boot time can
1377 give you some hints here ["man dmesg"].) Everyone needs either a
1378 coprocessor or this emulation.
1380 If you don't have a math coprocessor, you need to say Y here; if you
1381 say Y here even though you have a coprocessor, the coprocessor will
1382 be used nevertheless. (This behavior can be changed with the kernel
1383 command line option "no387", which comes handy if your coprocessor
1384 is broken. Try "man bootparam" or see the documentation of your boot
1385 loader (lilo or loadlin) about how to pass options to the kernel at
1386 boot time.) This means that it is a good idea to say Y here if you
1387 intend to use this kernel on different machines.
1389 More information about the internals of the Linux math coprocessor
1390 emulation can be found in <file:arch/x86/math-emu/README>.
1392 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1393 kernel, it won't hurt.
1395 config MTRR
1396 def_bool y
1397 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1398 ---help---
1399 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1400 the Memory Type Range Registers (MTRRs) may be used to control
1401 processor access to memory ranges. This is most useful if you have
1402 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1403 allows bus write transfers to be combined into a larger transfer
1404 before bursting over the PCI/AGP bus. This can increase performance
1405 of image write operations 2.5 times or more. Saying Y here creates a
1406 /proc/mtrr file which may be used to manipulate your processor's
1407 MTRRs. Typically the X server should use this.
1409 This code has a reasonably generic interface so that similar
1410 control registers on other processors can be easily supported
1411 as well:
1413 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1414 Registers (ARRs) which provide a similar functionality to MTRRs. For
1415 these, the ARRs are used to emulate the MTRRs.
1416 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1417 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1418 write-combining. All of these processors are supported by this code
1419 and it makes sense to say Y here if you have one of them.
1421 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1422 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1423 can lead to all sorts of problems, so it's good to say Y here.
1425 You can safely say Y even if your machine doesn't have MTRRs, you'll
1426 just add about 9 KB to your kernel.
1428 See <file:Documentation/x86/mtrr.txt> for more information.
1430 config MTRR_SANITIZER
1431 def_bool y
1432 prompt "MTRR cleanup support"
1433 depends on MTRR
1434 ---help---
1435 Convert MTRR layout from continuous to discrete, so X drivers can
1436 add writeback entries.
1438 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1439 The largest mtrr entry size for a continuous block can be set with
1440 mtrr_chunk_size.
1442 If unsure, say Y.
1444 config MTRR_SANITIZER_ENABLE_DEFAULT
1445 int "MTRR cleanup enable value (0-1)"
1446 range 0 1
1447 default "0"
1448 depends on MTRR_SANITIZER
1449 ---help---
1450 Enable mtrr cleanup default value
1452 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1453 int "MTRR cleanup spare reg num (0-7)"
1454 range 0 7
1455 default "1"
1456 depends on MTRR_SANITIZER
1457 ---help---
1458 mtrr cleanup spare entries default, it can be changed via
1459 mtrr_spare_reg_nr=N on the kernel command line.
1461 config X86_PAT
1462 def_bool y
1463 prompt "x86 PAT support" if EXPERT
1464 depends on MTRR
1465 ---help---
1466 Use PAT attributes to setup page level cache control.
1468 PATs are the modern equivalents of MTRRs and are much more
1469 flexible than MTRRs.
1471 Say N here if you see bootup problems (boot crash, boot hang,
1472 spontaneous reboots) or a non-working video driver.
1474 If unsure, say Y.
1476 config ARCH_USES_PG_UNCACHED
1477 def_bool y
1478 depends on X86_PAT
1480 config ARCH_RANDOM
1481 def_bool y
1482 prompt "x86 architectural random number generator" if EXPERT
1483 ---help---
1484 Enable the x86 architectural RDRAND instruction
1485 (Intel Bull Mountain technology) to generate random numbers.
1486 If supported, this is a high bandwidth, cryptographically
1487 secure hardware random number generator.
1489 config X86_SMAP
1490 def_bool y
1491 prompt "Supervisor Mode Access Prevention" if EXPERT
1492 ---help---
1493 Supervisor Mode Access Prevention (SMAP) is a security
1494 feature in newer Intel processors. There is a small
1495 performance cost if this enabled and turned on; there is
1496 also a small increase in the kernel size if this is enabled.
1498 If unsure, say Y.
1500 config EFI
1501 bool "EFI runtime service support"
1502 depends on ACPI
1503 select UCS2_STRING
1504 ---help---
1505 This enables the kernel to use EFI runtime services that are
1506 available (such as the EFI variable services).
1508 This option is only useful on systems that have EFI firmware.
1509 In addition, you should use the latest ELILO loader available
1510 at <http://elilo.sourceforge.net> in order to take advantage
1511 of EFI runtime services. However, even with this option, the
1512 resultant kernel should continue to boot on existing non-EFI
1513 platforms.
1515 config EFI_STUB
1516 bool "EFI stub support"
1517 depends on EFI
1518 ---help---
1519 This kernel feature allows a bzImage to be loaded directly
1520 by EFI firmware without the use of a bootloader.
1522 See Documentation/efi-stub.txt for more information.
1524 config EFI_MIXED
1525 bool "EFI mixed-mode support"
1526 depends on EFI_STUB && X86_64
1527 ---help---
1528 Enabling this feature allows a 64-bit kernel to be booted
1529 on a 32-bit firmware, provided that your CPU supports 64-bit
1530 mode.
1532 Note that it is not possible to boot a mixed-mode enabled
1533 kernel via the EFI boot stub - a bootloader that supports
1534 the EFI handover protocol must be used.
1536 If unsure, say N.
1538 config SECCOMP
1539 def_bool y
1540 prompt "Enable seccomp to safely compute untrusted bytecode"
1541 ---help---
1542 This kernel feature is useful for number crunching applications
1543 that may need to compute untrusted bytecode during their
1544 execution. By using pipes or other transports made available to
1545 the process as file descriptors supporting the read/write
1546 syscalls, it's possible to isolate those applications in
1547 their own address space using seccomp. Once seccomp is
1548 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1549 and the task is only allowed to execute a few safe syscalls
1550 defined by each seccomp mode.
1552 If unsure, say Y. Only embedded should say N here.
1554 source kernel/Kconfig.hz
1556 config KEXEC
1557 bool "kexec system call"
1558 ---help---
1559 kexec is a system call that implements the ability to shutdown your
1560 current kernel, and to start another kernel. It is like a reboot
1561 but it is independent of the system firmware. And like a reboot
1562 you can start any kernel with it, not just Linux.
1564 The name comes from the similarity to the exec system call.
1566 It is an ongoing process to be certain the hardware in a machine
1567 is properly shutdown, so do not be surprised if this code does not
1568 initially work for you. As of this writing the exact hardware
1569 interface is strongly in flux, so no good recommendation can be
1570 made.
1572 config CRASH_DUMP
1573 bool "kernel crash dumps"
1574 depends on X86_64 || (X86_32 && HIGHMEM)
1575 ---help---
1576 Generate crash dump after being started by kexec.
1577 This should be normally only set in special crash dump kernels
1578 which are loaded in the main kernel with kexec-tools into
1579 a specially reserved region and then later executed after
1580 a crash by kdump/kexec. The crash dump kernel must be compiled
1581 to a memory address not used by the main kernel or BIOS using
1582 PHYSICAL_START, or it must be built as a relocatable image
1583 (CONFIG_RELOCATABLE=y).
1584 For more details see Documentation/kdump/kdump.txt
1586 config KEXEC_JUMP
1587 bool "kexec jump"
1588 depends on KEXEC && HIBERNATION
1589 ---help---
1590 Jump between original kernel and kexeced kernel and invoke
1591 code in physical address mode via KEXEC
1593 config PHYSICAL_START
1594 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1595 default "0x1000000"
1596 ---help---
1597 This gives the physical address where the kernel is loaded.
1599 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1600 bzImage will decompress itself to above physical address and
1601 run from there. Otherwise, bzImage will run from the address where
1602 it has been loaded by the boot loader and will ignore above physical
1603 address.
1605 In normal kdump cases one does not have to set/change this option
1606 as now bzImage can be compiled as a completely relocatable image
1607 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1608 address. This option is mainly useful for the folks who don't want
1609 to use a bzImage for capturing the crash dump and want to use a
1610 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1611 to be specifically compiled to run from a specific memory area
1612 (normally a reserved region) and this option comes handy.
1614 So if you are using bzImage for capturing the crash dump,
1615 leave the value here unchanged to 0x1000000 and set
1616 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1617 for capturing the crash dump change this value to start of
1618 the reserved region. In other words, it can be set based on
1619 the "X" value as specified in the "crashkernel=YM@XM"
1620 command line boot parameter passed to the panic-ed
1621 kernel. Please take a look at Documentation/kdump/kdump.txt
1622 for more details about crash dumps.
1624 Usage of bzImage for capturing the crash dump is recommended as
1625 one does not have to build two kernels. Same kernel can be used
1626 as production kernel and capture kernel. Above option should have
1627 gone away after relocatable bzImage support is introduced. But it
1628 is present because there are users out there who continue to use
1629 vmlinux for dump capture. This option should go away down the
1630 line.
1632 Don't change this unless you know what you are doing.
1634 config RELOCATABLE
1635 bool "Build a relocatable kernel"
1636 default y
1637 ---help---
1638 This builds a kernel image that retains relocation information
1639 so it can be loaded someplace besides the default 1MB.
1640 The relocations tend to make the kernel binary about 10% larger,
1641 but are discarded at runtime.
1643 One use is for the kexec on panic case where the recovery kernel
1644 must live at a different physical address than the primary
1645 kernel.
1647 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1648 it has been loaded at and the compile time physical address
1649 (CONFIG_PHYSICAL_START) is used as the minimum location.
1651 config RANDOMIZE_BASE
1652 bool "Randomize the address of the kernel image"
1653 depends on RELOCATABLE
1654 depends on !HIBERNATION
1655 default n
1656 ---help---
1657 Randomizes the physical and virtual address at which the
1658 kernel image is decompressed, as a security feature that
1659 deters exploit attempts relying on knowledge of the location
1660 of kernel internals.
1662 Entropy is generated using the RDRAND instruction if it is
1663 supported. If RDTSC is supported, it is used as well. If
1664 neither RDRAND nor RDTSC are supported, then randomness is
1665 read from the i8254 timer.
1667 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1668 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1669 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1670 minimum of 2MiB, only 10 bits of entropy is theoretically
1671 possible. At best, due to page table layouts, 64-bit can use
1672 9 bits of entropy and 32-bit uses 8 bits.
1674 If unsure, say N.
1676 config RANDOMIZE_BASE_MAX_OFFSET
1677 hex "Maximum kASLR offset allowed" if EXPERT
1678 depends on RANDOMIZE_BASE
1679 range 0x0 0x20000000 if X86_32
1680 default "0x20000000" if X86_32
1681 range 0x0 0x40000000 if X86_64
1682 default "0x40000000" if X86_64
1683 ---help---
1684 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1685 memory is used to determine the maximal offset in bytes that will
1686 be applied to the kernel when kernel Address Space Layout
1687 Randomization (kASLR) is active. This must be a multiple of
1688 PHYSICAL_ALIGN.
1690 On 32-bit this is limited to 512MiB by page table layouts. The
1691 default is 512MiB.
1693 On 64-bit this is limited by how the kernel fixmap page table is
1694 positioned, so this cannot be larger than 1GiB currently. Without
1695 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1696 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1697 modules area will shrink to compensate, up to the current maximum
1698 1GiB to 1GiB split. The default is 1GiB.
1700 If unsure, leave at the default value.
1702 # Relocation on x86 needs some additional build support
1703 config X86_NEED_RELOCS
1704 def_bool y
1705 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1707 config PHYSICAL_ALIGN
1708 hex "Alignment value to which kernel should be aligned"
1709 default "0x200000"
1710 range 0x2000 0x1000000 if X86_32
1711 range 0x200000 0x1000000 if X86_64
1712 ---help---
1713 This value puts the alignment restrictions on physical address
1714 where kernel is loaded and run from. Kernel is compiled for an
1715 address which meets above alignment restriction.
1717 If bootloader loads the kernel at a non-aligned address and
1718 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1719 address aligned to above value and run from there.
1721 If bootloader loads the kernel at a non-aligned address and
1722 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1723 load address and decompress itself to the address it has been
1724 compiled for and run from there. The address for which kernel is
1725 compiled already meets above alignment restrictions. Hence the
1726 end result is that kernel runs from a physical address meeting
1727 above alignment restrictions.
1729 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1730 this value must be a multiple of 0x200000.
1732 Don't change this unless you know what you are doing.
1734 config HOTPLUG_CPU
1735 bool "Support for hot-pluggable CPUs"
1736 depends on SMP
1737 ---help---
1738 Say Y here to allow turning CPUs off and on. CPUs can be
1739 controlled through /sys/devices/system/cpu.
1740 ( Note: power management support will enable this option
1741 automatically on SMP systems. )
1742 Say N if you want to disable CPU hotplug.
1744 config BOOTPARAM_HOTPLUG_CPU0
1745 bool "Set default setting of cpu0_hotpluggable"
1746 default n
1747 depends on HOTPLUG_CPU
1748 ---help---
1749 Set whether default state of cpu0_hotpluggable is on or off.
1751 Say Y here to enable CPU0 hotplug by default. If this switch
1752 is turned on, there is no need to give cpu0_hotplug kernel
1753 parameter and the CPU0 hotplug feature is enabled by default.
1755 Please note: there are two known CPU0 dependencies if you want
1756 to enable the CPU0 hotplug feature either by this switch or by
1757 cpu0_hotplug kernel parameter.
1759 First, resume from hibernate or suspend always starts from CPU0.
1760 So hibernate and suspend are prevented if CPU0 is offline.
1762 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1763 offline if any interrupt can not migrate out of CPU0. There may
1764 be other CPU0 dependencies.
1766 Please make sure the dependencies are under your control before
1767 you enable this feature.
1769 Say N if you don't want to enable CPU0 hotplug feature by default.
1770 You still can enable the CPU0 hotplug feature at boot by kernel
1771 parameter cpu0_hotplug.
1773 config DEBUG_HOTPLUG_CPU0
1774 def_bool n
1775 prompt "Debug CPU0 hotplug"
1776 depends on HOTPLUG_CPU
1777 ---help---
1778 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1779 soon as possible and boots up userspace with CPU0 offlined. User
1780 can online CPU0 back after boot time.
1782 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1783 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1784 compilation or giving cpu0_hotplug kernel parameter at boot.
1786 If unsure, say N.
1788 config COMPAT_VDSO
1789 def_bool n
1790 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1791 depends on X86_32 || IA32_EMULATION
1792 ---help---
1793 Certain buggy versions of glibc will crash if they are
1794 presented with a 32-bit vDSO that is not mapped at the address
1795 indicated in its segment table.
1797 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1798 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1799 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1800 the only released version with the bug, but OpenSUSE 9
1801 contains a buggy "glibc 2.3.2".
1803 The symptom of the bug is that everything crashes on startup, saying:
1804 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1806 Saying Y here changes the default value of the vdso32 boot
1807 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1808 This works around the glibc bug but hurts performance.
1810 If unsure, say N: if you are compiling your own kernel, you
1811 are unlikely to be using a buggy version of glibc.
1813 config CMDLINE_BOOL
1814 bool "Built-in kernel command line"
1815 ---help---
1816 Allow for specifying boot arguments to the kernel at
1817 build time. On some systems (e.g. embedded ones), it is
1818 necessary or convenient to provide some or all of the
1819 kernel boot arguments with the kernel itself (that is,
1820 to not rely on the boot loader to provide them.)
1822 To compile command line arguments into the kernel,
1823 set this option to 'Y', then fill in the
1824 the boot arguments in CONFIG_CMDLINE.
1826 Systems with fully functional boot loaders (i.e. non-embedded)
1827 should leave this option set to 'N'.
1829 config CMDLINE
1830 string "Built-in kernel command string"
1831 depends on CMDLINE_BOOL
1832 default ""
1833 ---help---
1834 Enter arguments here that should be compiled into the kernel
1835 image and used at boot time. If the boot loader provides a
1836 command line at boot time, it is appended to this string to
1837 form the full kernel command line, when the system boots.
1839 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1840 change this behavior.
1842 In most cases, the command line (whether built-in or provided
1843 by the boot loader) should specify the device for the root
1844 file system.
1846 config CMDLINE_OVERRIDE
1847 bool "Built-in command line overrides boot loader arguments"
1848 depends on CMDLINE_BOOL
1849 ---help---
1850 Set this option to 'Y' to have the kernel ignore the boot loader
1851 command line, and use ONLY the built-in command line.
1853 This is used to work around broken boot loaders. This should
1854 be set to 'N' under normal conditions.
1856 endmenu
1858 config ARCH_ENABLE_MEMORY_HOTPLUG
1859 def_bool y
1860 depends on X86_64 || (X86_32 && HIGHMEM)
1862 config ARCH_ENABLE_MEMORY_HOTREMOVE
1863 def_bool y
1864 depends on MEMORY_HOTPLUG
1866 config USE_PERCPU_NUMA_NODE_ID
1867 def_bool y
1868 depends on NUMA
1870 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1871 def_bool y
1872 depends on X86_64 || X86_PAE
1874 menu "Power management and ACPI options"
1876 config ARCH_HIBERNATION_HEADER
1877 def_bool y
1878 depends on X86_64 && HIBERNATION
1880 source "kernel/power/Kconfig"
1882 source "drivers/acpi/Kconfig"
1884 source "drivers/sfi/Kconfig"
1886 config X86_APM_BOOT
1887 def_bool y
1888 depends on APM
1890 menuconfig APM
1891 tristate "APM (Advanced Power Management) BIOS support"
1892 depends on X86_32 && PM_SLEEP
1893 ---help---
1894 APM is a BIOS specification for saving power using several different
1895 techniques. This is mostly useful for battery powered laptops with
1896 APM compliant BIOSes. If you say Y here, the system time will be
1897 reset after a RESUME operation, the /proc/apm device will provide
1898 battery status information, and user-space programs will receive
1899 notification of APM "events" (e.g. battery status change).
1901 If you select "Y" here, you can disable actual use of the APM
1902 BIOS by passing the "apm=off" option to the kernel at boot time.
1904 Note that the APM support is almost completely disabled for
1905 machines with more than one CPU.
1907 In order to use APM, you will need supporting software. For location
1908 and more information, read <file:Documentation/power/apm-acpi.txt>
1909 and the Battery Powered Linux mini-HOWTO, available from
1910 <http://www.tldp.org/docs.html#howto>.
1912 This driver does not spin down disk drives (see the hdparm(8)
1913 manpage ("man 8 hdparm") for that), and it doesn't turn off
1914 VESA-compliant "green" monitors.
1916 This driver does not support the TI 4000M TravelMate and the ACER
1917 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1918 desktop machines also don't have compliant BIOSes, and this driver
1919 may cause those machines to panic during the boot phase.
1921 Generally, if you don't have a battery in your machine, there isn't
1922 much point in using this driver and you should say N. If you get
1923 random kernel OOPSes or reboots that don't seem to be related to
1924 anything, try disabling/enabling this option (or disabling/enabling
1925 APM in your BIOS).
1927 Some other things you should try when experiencing seemingly random,
1928 "weird" problems:
1930 1) make sure that you have enough swap space and that it is
1931 enabled.
1932 2) pass the "no-hlt" option to the kernel
1933 3) switch on floating point emulation in the kernel and pass
1934 the "no387" option to the kernel
1935 4) pass the "floppy=nodma" option to the kernel
1936 5) pass the "mem=4M" option to the kernel (thereby disabling
1937 all but the first 4 MB of RAM)
1938 6) make sure that the CPU is not over clocked.
1939 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1940 8) disable the cache from your BIOS settings
1941 9) install a fan for the video card or exchange video RAM
1942 10) install a better fan for the CPU
1943 11) exchange RAM chips
1944 12) exchange the motherboard.
1946 To compile this driver as a module, choose M here: the
1947 module will be called apm.
1949 if APM
1951 config APM_IGNORE_USER_SUSPEND
1952 bool "Ignore USER SUSPEND"
1953 ---help---
1954 This option will ignore USER SUSPEND requests. On machines with a
1955 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1956 series notebooks, it is necessary to say Y because of a BIOS bug.
1958 config APM_DO_ENABLE
1959 bool "Enable PM at boot time"
1960 ---help---
1961 Enable APM features at boot time. From page 36 of the APM BIOS
1962 specification: "When disabled, the APM BIOS does not automatically
1963 power manage devices, enter the Standby State, enter the Suspend
1964 State, or take power saving steps in response to CPU Idle calls."
1965 This driver will make CPU Idle calls when Linux is idle (unless this
1966 feature is turned off -- see "Do CPU IDLE calls", below). This
1967 should always save battery power, but more complicated APM features
1968 will be dependent on your BIOS implementation. You may need to turn
1969 this option off if your computer hangs at boot time when using APM
1970 support, or if it beeps continuously instead of suspending. Turn
1971 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1972 T400CDT. This is off by default since most machines do fine without
1973 this feature.
1975 config APM_CPU_IDLE
1976 depends on CPU_IDLE
1977 bool "Make CPU Idle calls when idle"
1978 ---help---
1979 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1980 On some machines, this can activate improved power savings, such as
1981 a slowed CPU clock rate, when the machine is idle. These idle calls
1982 are made after the idle loop has run for some length of time (e.g.,
1983 333 mS). On some machines, this will cause a hang at boot time or
1984 whenever the CPU becomes idle. (On machines with more than one CPU,
1985 this option does nothing.)
1987 config APM_DISPLAY_BLANK
1988 bool "Enable console blanking using APM"
1989 ---help---
1990 Enable console blanking using the APM. Some laptops can use this to
1991 turn off the LCD backlight when the screen blanker of the Linux
1992 virtual console blanks the screen. Note that this is only used by
1993 the virtual console screen blanker, and won't turn off the backlight
1994 when using the X Window system. This also doesn't have anything to
1995 do with your VESA-compliant power-saving monitor. Further, this
1996 option doesn't work for all laptops -- it might not turn off your
1997 backlight at all, or it might print a lot of errors to the console,
1998 especially if you are using gpm.
2000 config APM_ALLOW_INTS
2001 bool "Allow interrupts during APM BIOS calls"
2002 ---help---
2003 Normally we disable external interrupts while we are making calls to
2004 the APM BIOS as a measure to lessen the effects of a badly behaving
2005 BIOS implementation. The BIOS should reenable interrupts if it
2006 needs to. Unfortunately, some BIOSes do not -- especially those in
2007 many of the newer IBM Thinkpads. If you experience hangs when you
2008 suspend, try setting this to Y. Otherwise, say N.
2010 endif # APM
2012 source "drivers/cpufreq/Kconfig"
2014 source "drivers/cpuidle/Kconfig"
2016 source "drivers/idle/Kconfig"
2018 endmenu
2021 menu "Bus options (PCI etc.)"
2023 config PCI
2024 bool "PCI support"
2025 default y
2026 ---help---
2027 Find out whether you have a PCI motherboard. PCI is the name of a
2028 bus system, i.e. the way the CPU talks to the other stuff inside
2029 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2030 VESA. If you have PCI, say Y, otherwise N.
2032 choice
2033 prompt "PCI access mode"
2034 depends on X86_32 && PCI
2035 default PCI_GOANY
2036 ---help---
2037 On PCI systems, the BIOS can be used to detect the PCI devices and
2038 determine their configuration. However, some old PCI motherboards
2039 have BIOS bugs and may crash if this is done. Also, some embedded
2040 PCI-based systems don't have any BIOS at all. Linux can also try to
2041 detect the PCI hardware directly without using the BIOS.
2043 With this option, you can specify how Linux should detect the
2044 PCI devices. If you choose "BIOS", the BIOS will be used,
2045 if you choose "Direct", the BIOS won't be used, and if you
2046 choose "MMConfig", then PCI Express MMCONFIG will be used.
2047 If you choose "Any", the kernel will try MMCONFIG, then the
2048 direct access method and falls back to the BIOS if that doesn't
2049 work. If unsure, go with the default, which is "Any".
2051 config PCI_GOBIOS
2052 bool "BIOS"
2054 config PCI_GOMMCONFIG
2055 bool "MMConfig"
2057 config PCI_GODIRECT
2058 bool "Direct"
2060 config PCI_GOOLPC
2061 bool "OLPC XO-1"
2062 depends on OLPC
2064 config PCI_GOANY
2065 bool "Any"
2067 endchoice
2069 config PCI_BIOS
2070 def_bool y
2071 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2073 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2074 config PCI_DIRECT
2075 def_bool y
2076 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2078 config PCI_MMCONFIG
2079 def_bool y
2080 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2082 config PCI_OLPC
2083 def_bool y
2084 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2086 config PCI_XEN
2087 def_bool y
2088 depends on PCI && XEN
2089 select SWIOTLB_XEN
2091 config PCI_DOMAINS
2092 def_bool y
2093 depends on PCI
2095 config PCI_MMCONFIG
2096 bool "Support mmconfig PCI config space access"
2097 depends on X86_64 && PCI && ACPI
2099 config PCI_CNB20LE_QUIRK
2100 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2101 depends on PCI
2102 help
2103 Read the PCI windows out of the CNB20LE host bridge. This allows
2104 PCI hotplug to work on systems with the CNB20LE chipset which do
2105 not have ACPI.
2107 There's no public spec for this chipset, and this functionality
2108 is known to be incomplete.
2110 You should say N unless you know you need this.
2112 source "drivers/pci/pcie/Kconfig"
2114 source "drivers/pci/Kconfig"
2116 # x86_64 have no ISA slots, but can have ISA-style DMA.
2117 config ISA_DMA_API
2118 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2119 default y
2120 help
2121 Enables ISA-style DMA support for devices requiring such controllers.
2122 If unsure, say Y.
2124 if X86_32
2126 config ISA
2127 bool "ISA support"
2128 ---help---
2129 Find out whether you have ISA slots on your motherboard. ISA is the
2130 name of a bus system, i.e. the way the CPU talks to the other stuff
2131 inside your box. Other bus systems are PCI, EISA, MicroChannel
2132 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2133 newer boards don't support it. If you have ISA, say Y, otherwise N.
2135 config EISA
2136 bool "EISA support"
2137 depends on ISA
2138 ---help---
2139 The Extended Industry Standard Architecture (EISA) bus was
2140 developed as an open alternative to the IBM MicroChannel bus.
2142 The EISA bus provided some of the features of the IBM MicroChannel
2143 bus while maintaining backward compatibility with cards made for
2144 the older ISA bus. The EISA bus saw limited use between 1988 and
2145 1995 when it was made obsolete by the PCI bus.
2147 Say Y here if you are building a kernel for an EISA-based machine.
2149 Otherwise, say N.
2151 source "drivers/eisa/Kconfig"
2153 config SCx200
2154 tristate "NatSemi SCx200 support"
2155 ---help---
2156 This provides basic support for National Semiconductor's
2157 (now AMD's) Geode processors. The driver probes for the
2158 PCI-IDs of several on-chip devices, so its a good dependency
2159 for other scx200_* drivers.
2161 If compiled as a module, the driver is named scx200.
2163 config SCx200HR_TIMER
2164 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2165 depends on SCx200
2166 default y
2167 ---help---
2168 This driver provides a clocksource built upon the on-chip
2169 27MHz high-resolution timer. Its also a workaround for
2170 NSC Geode SC-1100's buggy TSC, which loses time when the
2171 processor goes idle (as is done by the scheduler). The
2172 other workaround is idle=poll boot option.
2174 config OLPC
2175 bool "One Laptop Per Child support"
2176 depends on !X86_PAE
2177 select GPIOLIB
2178 select OF
2179 select OF_PROMTREE
2180 select IRQ_DOMAIN
2181 ---help---
2182 Add support for detecting the unique features of the OLPC
2183 XO hardware.
2185 config OLPC_XO1_PM
2186 bool "OLPC XO-1 Power Management"
2187 depends on OLPC && MFD_CS5535 && PM_SLEEP
2188 select MFD_CORE
2189 ---help---
2190 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2192 config OLPC_XO1_RTC
2193 bool "OLPC XO-1 Real Time Clock"
2194 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2195 ---help---
2196 Add support for the XO-1 real time clock, which can be used as a
2197 programmable wakeup source.
2199 config OLPC_XO1_SCI
2200 bool "OLPC XO-1 SCI extras"
2201 depends on OLPC && OLPC_XO1_PM
2202 depends on INPUT=y
2203 select POWER_SUPPLY
2204 select GPIO_CS5535
2205 select MFD_CORE
2206 ---help---
2207 Add support for SCI-based features of the OLPC XO-1 laptop:
2208 - EC-driven system wakeups
2209 - Power button
2210 - Ebook switch
2211 - Lid switch
2212 - AC adapter status updates
2213 - Battery status updates
2215 config OLPC_XO15_SCI
2216 bool "OLPC XO-1.5 SCI extras"
2217 depends on OLPC && ACPI
2218 select POWER_SUPPLY
2219 ---help---
2220 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2221 - EC-driven system wakeups
2222 - AC adapter status updates
2223 - Battery status updates
2225 config ALIX
2226 bool "PCEngines ALIX System Support (LED setup)"
2227 select GPIOLIB
2228 ---help---
2229 This option enables system support for the PCEngines ALIX.
2230 At present this just sets up LEDs for GPIO control on
2231 ALIX2/3/6 boards. However, other system specific setup should
2232 get added here.
2234 Note: You must still enable the drivers for GPIO and LED support
2235 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2237 Note: You have to set alix.force=1 for boards with Award BIOS.
2239 config NET5501
2240 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2241 select GPIOLIB
2242 ---help---
2243 This option enables system support for the Soekris Engineering net5501.
2245 config GEOS
2246 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2247 select GPIOLIB
2248 depends on DMI
2249 ---help---
2250 This option enables system support for the Traverse Technologies GEOS.
2252 config TS5500
2253 bool "Technologic Systems TS-5500 platform support"
2254 depends on MELAN
2255 select CHECK_SIGNATURE
2256 select NEW_LEDS
2257 select LEDS_CLASS
2258 ---help---
2259 This option enables system support for the Technologic Systems TS-5500.
2261 endif # X86_32
2263 config AMD_NB
2264 def_bool y
2265 depends on CPU_SUP_AMD && PCI
2267 source "drivers/pcmcia/Kconfig"
2269 source "drivers/pci/hotplug/Kconfig"
2271 config RAPIDIO
2272 tristate "RapidIO support"
2273 depends on PCI
2274 default n
2275 help
2276 If enabled this option will include drivers and the core
2277 infrastructure code to support RapidIO interconnect devices.
2279 source "drivers/rapidio/Kconfig"
2281 config X86_SYSFB
2282 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2283 help
2284 Firmwares often provide initial graphics framebuffers so the BIOS,
2285 bootloader or kernel can show basic video-output during boot for
2286 user-guidance and debugging. Historically, x86 used the VESA BIOS
2287 Extensions and EFI-framebuffers for this, which are mostly limited
2288 to x86.
2289 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2290 framebuffers so the new generic system-framebuffer drivers can be
2291 used on x86. If the framebuffer is not compatible with the generic
2292 modes, it is adverticed as fallback platform framebuffer so legacy
2293 drivers like efifb, vesafb and uvesafb can pick it up.
2294 If this option is not selected, all system framebuffers are always
2295 marked as fallback platform framebuffers as usual.
2297 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2298 not be able to pick up generic system framebuffers if this option
2299 is selected. You are highly encouraged to enable simplefb as
2300 replacement if you select this option. simplefb can correctly deal
2301 with generic system framebuffers. But you should still keep vesafb
2302 and others enabled as fallback if a system framebuffer is
2303 incompatible with simplefb.
2305 If unsure, say Y.
2307 endmenu
2310 menu "Executable file formats / Emulations"
2312 source "fs/Kconfig.binfmt"
2314 config IA32_EMULATION
2315 bool "IA32 Emulation"
2316 depends on X86_64
2317 select BINFMT_ELF
2318 select COMPAT_BINFMT_ELF
2319 select HAVE_UID16
2320 ---help---
2321 Include code to run legacy 32-bit programs under a
2322 64-bit kernel. You should likely turn this on, unless you're
2323 100% sure that you don't have any 32-bit programs left.
2325 config IA32_AOUT
2326 tristate "IA32 a.out support"
2327 depends on IA32_EMULATION
2328 ---help---
2329 Support old a.out binaries in the 32bit emulation.
2331 config X86_X32
2332 bool "x32 ABI for 64-bit mode"
2333 depends on X86_64 && IA32_EMULATION
2334 ---help---
2335 Include code to run binaries for the x32 native 32-bit ABI
2336 for 64-bit processors. An x32 process gets access to the
2337 full 64-bit register file and wide data path while leaving
2338 pointers at 32 bits for smaller memory footprint.
2340 You will need a recent binutils (2.22 or later) with
2341 elf32_x86_64 support enabled to compile a kernel with this
2342 option set.
2344 config COMPAT
2345 def_bool y
2346 depends on IA32_EMULATION || X86_X32
2347 select ARCH_WANT_OLD_COMPAT_IPC
2349 if COMPAT
2350 config COMPAT_FOR_U64_ALIGNMENT
2351 def_bool y
2353 config SYSVIPC_COMPAT
2354 def_bool y
2355 depends on SYSVIPC
2357 config KEYS_COMPAT
2358 def_bool y
2359 depends on KEYS
2360 endif
2362 endmenu
2365 config HAVE_ATOMIC_IOMAP
2366 def_bool y
2367 depends on X86_32
2369 config X86_DEV_DMA_OPS
2370 bool
2371 depends on X86_64 || STA2X11
2373 config X86_DMA_REMAP
2374 bool
2375 depends on STA2X11
2377 config IOSF_MBI
2378 bool
2379 depends on PCI
2380 ---help---
2381 To be selected by modules requiring access to the Intel OnChip System
2382 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2383 enumerable by PCI.
2385 source "net/Kconfig"
2387 source "drivers/Kconfig"
2389 source "drivers/firmware/Kconfig"
2391 source "fs/Kconfig"
2393 source "arch/x86/Kconfig.debug"
2395 source "security/Kconfig"
2397 source "crypto/Kconfig"
2399 source "arch/x86/kvm/Kconfig"
2401 source "lib/Kconfig"