| blob | ed92864d1325c09092f3e8ed4918f26341f23161 |
1 # x86 configuration
2 mainmenu "Linux Kernel Configuration for x86"
4 # Select 32 or 64 bit
5 config 64BIT
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
8 help
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
12 config X86_32
13 def_bool !64BIT
15 config X86_64
16 def_bool 64BIT
18 ### Arch settings
19 config X86
20 def_bool y
21 select HAVE_UNSTABLE_SCHED_CLOCK
22 select HAVE_IDE
23 select HAVE_OPROFILE
24 select HAVE_IOREMAP_PROT
25 select HAVE_KPROBES
26 select ARCH_WANT_OPTIONAL_GPIOLIB
27 select HAVE_KRETPROBES
28 select HAVE_DYNAMIC_FTRACE
29 select HAVE_FTRACE
30 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
31 select HAVE_ARCH_KGDB if !X86_VOYAGER
32 select HAVE_GENERIC_DMA_COHERENT if X86_32
33 select HAVE_EFFICIENT_UNALIGNED_ACCESS
35 config ARCH_DEFCONFIG
36 string
37 default "arch/x86/configs/i386_defconfig" if X86_32
38 default "arch/x86/configs/x86_64_defconfig" if X86_64
41 config GENERIC_LOCKBREAK
42 def_bool n
44 config GENERIC_TIME
45 def_bool y
47 config GENERIC_CMOS_UPDATE
48 def_bool y
50 config CLOCKSOURCE_WATCHDOG
51 def_bool y
53 config GENERIC_CLOCKEVENTS
54 def_bool y
56 config GENERIC_CLOCKEVENTS_BROADCAST
57 def_bool y
58 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
60 config LOCKDEP_SUPPORT
61 def_bool y
63 config STACKTRACE_SUPPORT
64 def_bool y
66 config HAVE_LATENCYTOP_SUPPORT
67 def_bool y
69 config FAST_CMPXCHG_LOCAL
70 bool
71 default y
73 config MMU
74 def_bool y
76 config ZONE_DMA
77 def_bool y
79 config SBUS
80 bool
82 config GENERIC_ISA_DMA
83 def_bool y
85 config GENERIC_IOMAP
86 def_bool y
88 config GENERIC_BUG
89 def_bool y
90 depends on BUG
92 config GENERIC_HWEIGHT
93 def_bool y
95 config GENERIC_GPIO
96 def_bool n
98 config ARCH_MAY_HAVE_PC_FDC
99 def_bool y
101 config RWSEM_GENERIC_SPINLOCK
102 def_bool !X86_XADD
104 config RWSEM_XCHGADD_ALGORITHM
105 def_bool X86_XADD
107 config ARCH_HAS_ILOG2_U32
108 def_bool n
110 config ARCH_HAS_ILOG2_U64
111 def_bool n
113 config ARCH_HAS_CPU_IDLE_WAIT
114 def_bool y
116 config GENERIC_CALIBRATE_DELAY
117 def_bool y
119 config GENERIC_TIME_VSYSCALL
120 bool
121 default X86_64
123 config ARCH_HAS_CPU_RELAX
124 def_bool y
126 config ARCH_HAS_CACHE_LINE_SIZE
127 def_bool y
129 config HAVE_SETUP_PER_CPU_AREA
130 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
132 config HAVE_CPUMASK_OF_CPU_MAP
133 def_bool X86_64_SMP
135 config ARCH_HIBERNATION_POSSIBLE
136 def_bool y
137 depends on !SMP || !X86_VOYAGER
139 config ARCH_SUSPEND_POSSIBLE
140 def_bool y
141 depends on !X86_VOYAGER
143 config ZONE_DMA32
144 bool
145 default X86_64
147 config ARCH_POPULATES_NODE_MAP
148 def_bool y
150 config AUDIT_ARCH
151 bool
152 default X86_64
154 config ARCH_SUPPORTS_AOUT
155 def_bool y
157 config ARCH_SUPPORTS_OPTIMIZED_INLINING
158 def_bool y
160 # Use the generic interrupt handling code in kernel/irq/:
161 config GENERIC_HARDIRQS
162 bool
163 default y
165 config GENERIC_IRQ_PROBE
166 bool
167 default y
169 config GENERIC_PENDING_IRQ
170 bool
171 depends on GENERIC_HARDIRQS && SMP
172 default y
174 config X86_SMP
175 bool
176 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
177 select USE_GENERIC_SMP_HELPERS
178 default y
180 config X86_32_SMP
181 def_bool y
182 depends on X86_32 && SMP
184 config X86_64_SMP
185 def_bool y
186 depends on X86_64 && SMP
188 config X86_HT
189 bool
190 depends on SMP
191 depends on (X86_32 && !X86_VOYAGER) || X86_64
192 default y
194 config X86_BIOS_REBOOT
195 bool
196 depends on !X86_VOYAGER
197 default y
199 config X86_TRAMPOLINE
200 bool
201 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
202 default y
204 config KTIME_SCALAR
205 def_bool X86_32
206 source "init/Kconfig"
208 menu "Processor type and features"
210 source "kernel/time/Kconfig"
212 config SMP
213 bool "Symmetric multi-processing support"
214 ---help---
215 This enables support for systems with more than one CPU. If you have
216 a system with only one CPU, like most personal computers, say N. If
217 you have a system with more than one CPU, say Y.
219 If you say N here, the kernel will run on single and multiprocessor
220 machines, but will use only one CPU of a multiprocessor machine. If
221 you say Y here, the kernel will run on many, but not all,
222 singleprocessor machines. On a singleprocessor machine, the kernel
223 will run faster if you say N here.
225 Note that if you say Y here and choose architecture "586" or
226 "Pentium" under "Processor family", the kernel will not work on 486
227 architectures. Similarly, multiprocessor kernels for the "PPro"
228 architecture may not work on all Pentium based boards.
230 People using multiprocessor machines who say Y here should also say
231 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
232 Management" code will be disabled if you say Y here.
234 See also <file:Documentation/i386/IO-APIC.txt>,
235 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
236 <http://www.tldp.org/docs.html#howto>.
238 If you don't know what to do here, say N.
240 config X86_FIND_SMP_CONFIG
241 def_bool y
242 depends on X86_MPPARSE || X86_VOYAGER
244 if ACPI
245 config X86_MPPARSE
246 def_bool y
247 bool "Enable MPS table"
248 depends on X86_LOCAL_APIC
249 help
250 For old smp systems that do not have proper acpi support. Newer systems
251 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
252 endif
254 if !ACPI
255 config X86_MPPARSE
256 def_bool y
257 depends on X86_LOCAL_APIC
258 endif
260 choice
261 prompt "Subarchitecture Type"
262 default X86_PC
264 config X86_PC
265 bool "PC-compatible"
266 help
267 Choose this option if your computer is a standard PC or compatible.
269 config X86_ELAN
270 bool "AMD Elan"
271 depends on X86_32
272 help
273 Select this for an AMD Elan processor.
275 Do not use this option for K6/Athlon/Opteron processors!
277 If unsure, choose "PC-compatible" instead.
279 config X86_VOYAGER
280 bool "Voyager (NCR)"
281 depends on X86_32 && (SMP || BROKEN) && !PCI
282 help
283 Voyager is an MCA-based 32-way capable SMP architecture proprietary
284 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
286 *** WARNING ***
288 If you do not specifically know you have a Voyager based machine,
289 say N here, otherwise the kernel you build will not be bootable.
291 config X86_GENERICARCH
292 bool "Generic architecture"
293 depends on X86_32
294 help
295 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
296 subarchitectures. It is intended for a generic binary kernel.
297 if you select them all, kernel will probe it one by one. and will
298 fallback to default.
300 if X86_GENERICARCH
302 config X86_NUMAQ
303 bool "NUMAQ (IBM/Sequent)"
304 depends on SMP && X86_32 && PCI && X86_MPPARSE
305 select NUMA
306 help
307 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
308 NUMA multiquad box. This changes the way that processors are
309 bootstrapped, and uses Clustered Logical APIC addressing mode instead
310 of Flat Logical. You will need a new lynxer.elf file to flash your
311 firmware with - send email to <Martin.Bligh@us.ibm.com>.
313 config X86_SUMMIT
314 bool "Summit/EXA (IBM x440)"
315 depends on X86_32 && SMP
316 help
317 This option is needed for IBM systems that use the Summit/EXA chipset.
318 In particular, it is needed for the x440.
320 config X86_ES7000
321 bool "Support for Unisys ES7000 IA32 series"
322 depends on X86_32 && SMP
323 help
324 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
325 supposed to run on an IA32-based Unisys ES7000 system.
327 config X86_BIGSMP
328 bool "Support for big SMP systems with more than 8 CPUs"
329 depends on X86_32 && SMP
330 help
331 This option is needed for the systems that have more than 8 CPUs
332 and if the system is not of any sub-arch type above.
334 endif
336 config X86_VSMP
337 bool "Support for ScaleMP vSMP"
338 select PARAVIRT
339 depends on X86_64 && PCI
340 help
341 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
342 supposed to run on these EM64T-based machines. Only choose this option
343 if you have one of these machines.
345 endchoice
347 config X86_VISWS
348 bool "SGI 320/540 (Visual Workstation)"
349 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
350 help
351 The SGI Visual Workstation series is an IA32-based workstation
352 based on SGI systems chips with some legacy PC hardware attached.
354 Say Y here to create a kernel to run on the SGI 320 or 540.
356 A kernel compiled for the Visual Workstation will run on general
357 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
359 config X86_RDC321X
360 bool "RDC R-321x SoC"
361 depends on X86_32
362 select M486
363 select X86_REBOOTFIXUPS
364 help
365 This option is needed for RDC R-321x system-on-chip, also known
366 as R-8610-(G).
367 If you don't have one of these chips, you should say N here.
369 config SCHED_NO_NO_OMIT_FRAME_POINTER
370 def_bool y
371 prompt "Single-depth WCHAN output"
372 depends on X86_32
373 help
374 Calculate simpler /proc/<PID>/wchan values. If this option
375 is disabled then wchan values will recurse back to the
376 caller function. This provides more accurate wchan values,
377 at the expense of slightly more scheduling overhead.
379 If in doubt, say "Y".
381 menuconfig PARAVIRT_GUEST
382 bool "Paravirtualized guest support"
383 help
384 Say Y here to get to see options related to running Linux under
385 various hypervisors. This option alone does not add any kernel code.
387 If you say N, all options in this submenu will be skipped and disabled.
389 if PARAVIRT_GUEST
391 source "arch/x86/xen/Kconfig"
393 config VMI
394 bool "VMI Guest support"
395 select PARAVIRT
396 depends on X86_32
397 depends on !X86_VOYAGER
398 help
399 VMI provides a paravirtualized interface to the VMware ESX server
400 (it could be used by other hypervisors in theory too, but is not
401 at the moment), by linking the kernel to a GPL-ed ROM module
402 provided by the hypervisor.
404 config KVM_CLOCK
405 bool "KVM paravirtualized clock"
406 select PARAVIRT
407 select PARAVIRT_CLOCK
408 depends on !X86_VOYAGER
409 help
410 Turning on this option will allow you to run a paravirtualized clock
411 when running over the KVM hypervisor. Instead of relying on a PIT
412 (or probably other) emulation by the underlying device model, the host
413 provides the guest with timing infrastructure such as time of day, and
414 system time
416 config KVM_GUEST
417 bool "KVM Guest support"
418 select PARAVIRT
419 depends on !X86_VOYAGER
420 help
421 This option enables various optimizations for running under the KVM
422 hypervisor.
424 source "arch/x86/lguest/Kconfig"
426 config PARAVIRT
427 bool "Enable paravirtualization code"
428 depends on !X86_VOYAGER
429 help
430 This changes the kernel so it can modify itself when it is run
431 under a hypervisor, potentially improving performance significantly
432 over full virtualization. However, when run without a hypervisor
433 the kernel is theoretically slower and slightly larger.
435 config PARAVIRT_CLOCK
436 bool
437 default n
439 endif
441 config PARAVIRT_DEBUG
442 bool "paravirt-ops debugging"
443 depends on PARAVIRT && DEBUG_KERNEL
444 help
445 Enable to debug paravirt_ops internals. Specifically, BUG if
446 a paravirt_op is missing when it is called.
448 config MEMTEST
449 bool "Memtest"
450 help
451 This option adds a kernel parameter 'memtest', which allows memtest
452 to be set.
453 memtest=0, mean disabled; -- default
454 memtest=1, mean do 1 test pattern;
455 ...
456 memtest=4, mean do 4 test patterns.
457 If you are unsure how to answer this question, answer N.
459 config X86_SUMMIT_NUMA
460 def_bool y
461 depends on X86_32 && NUMA && X86_GENERICARCH
463 config X86_CYCLONE_TIMER
464 def_bool y
465 depends on X86_GENERICARCH
467 config ES7000_CLUSTERED_APIC
468 def_bool y
469 depends on SMP && X86_ES7000 && MPENTIUMIII
471 source "arch/x86/Kconfig.cpu"
473 config HPET_TIMER
474 def_bool X86_64
475 prompt "HPET Timer Support" if X86_32
476 help
477 Use the IA-PC HPET (High Precision Event Timer) to manage
478 time in preference to the PIT and RTC, if a HPET is
479 present.
480 HPET is the next generation timer replacing legacy 8254s.
481 The HPET provides a stable time base on SMP
482 systems, unlike the TSC, but it is more expensive to access,
483 as it is off-chip. You can find the HPET spec at
484 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
486 You can safely choose Y here. However, HPET will only be
487 activated if the platform and the BIOS support this feature.
488 Otherwise the 8254 will be used for timing services.
490 Choose N to continue using the legacy 8254 timer.
492 config HPET_EMULATE_RTC
493 def_bool y
494 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
496 # Mark as embedded because too many people got it wrong.
497 # The code disables itself when not needed.
498 config DMI
499 default y
500 bool "Enable DMI scanning" if EMBEDDED
501 help
502 Enabled scanning of DMI to identify machine quirks. Say Y
503 here unless you have verified that your setup is not
504 affected by entries in the DMI blacklist. Required by PNP
505 BIOS code.
507 config GART_IOMMU
508 bool "GART IOMMU support" if EMBEDDED
509 default y
510 select SWIOTLB
511 select AGP
512 depends on X86_64 && PCI
513 help
514 Support for full DMA access of devices with 32bit memory access only
515 on systems with more than 3GB. This is usually needed for USB,
516 sound, many IDE/SATA chipsets and some other devices.
517 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
518 based hardware IOMMU and a software bounce buffer based IOMMU used
519 on Intel systems and as fallback.
520 The code is only active when needed (enough memory and limited
521 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
522 too.
524 config CALGARY_IOMMU
525 bool "IBM Calgary IOMMU support"
526 select SWIOTLB
527 depends on X86_64 && PCI && EXPERIMENTAL
528 help
529 Support for hardware IOMMUs in IBM's xSeries x366 and x460
530 systems. Needed to run systems with more than 3GB of memory
531 properly with 32-bit PCI devices that do not support DAC
532 (Double Address Cycle). Calgary also supports bus level
533 isolation, where all DMAs pass through the IOMMU. This
534 prevents them from going anywhere except their intended
535 destination. This catches hard-to-find kernel bugs and
536 mis-behaving drivers and devices that do not use the DMA-API
537 properly to set up their DMA buffers. The IOMMU can be
538 turned off at boot time with the iommu=off parameter.
539 Normally the kernel will make the right choice by itself.
540 If unsure, say Y.
542 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
543 def_bool y
544 prompt "Should Calgary be enabled by default?"
545 depends on CALGARY_IOMMU
546 help
547 Should Calgary be enabled by default? if you choose 'y', Calgary
548 will be used (if it exists). If you choose 'n', Calgary will not be
549 used even if it exists. If you choose 'n' and would like to use
550 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
551 If unsure, say Y.
553 config AMD_IOMMU
554 bool "AMD IOMMU support"
555 select SWIOTLB
556 depends on X86_64 && PCI && ACPI
557 help
558 With this option you can enable support for AMD IOMMU hardware in
559 your system. An IOMMU is a hardware component which provides
560 remapping of DMA memory accesses from devices. With an AMD IOMMU you
561 can isolate the the DMA memory of different devices and protect the
562 system from misbehaving device drivers or hardware.
564 You can find out if your system has an AMD IOMMU if you look into
565 your BIOS for an option to enable it or if you have an IVRS ACPI
566 table.
568 # need this always selected by IOMMU for the VIA workaround
569 config SWIOTLB
570 bool
571 help
572 Support for software bounce buffers used on x86-64 systems
573 which don't have a hardware IOMMU (e.g. the current generation
574 of Intel's x86-64 CPUs). Using this PCI devices which can only
575 access 32-bits of memory can be used on systems with more than
576 3 GB of memory. If unsure, say Y.
578 config IOMMU_HELPER
579 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
581 config MAXSMP
582 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
583 depends on X86_64 && SMP && BROKEN
584 default n
585 help
586 Configure maximum number of CPUS and NUMA Nodes for this architecture.
587 If unsure, say N.
589 config NR_CPUS
590 int "Maximum number of CPUs (2-512)" if !MAXSMP
591 range 2 512
592 depends on SMP
593 default "4096" if MAXSMP
594 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
595 default "8"
596 help
597 This allows you to specify the maximum number of CPUs which this
598 kernel will support. The maximum supported value is 512 and the
599 minimum value which makes sense is 2.
601 This is purely to save memory - each supported CPU adds
602 approximately eight kilobytes to the kernel image.
604 config SCHED_SMT
605 bool "SMT (Hyperthreading) scheduler support"
606 depends on X86_HT
607 help
608 SMT scheduler support improves the CPU scheduler's decision making
609 when dealing with Intel Pentium 4 chips with HyperThreading at a
610 cost of slightly increased overhead in some places. If unsure say
611 N here.
613 config SCHED_MC
614 def_bool y
615 prompt "Multi-core scheduler support"
616 depends on X86_HT
617 help
618 Multi-core scheduler support improves the CPU scheduler's decision
619 making when dealing with multi-core CPU chips at a cost of slightly
620 increased overhead in some places. If unsure say N here.
622 source "kernel/Kconfig.preempt"
624 config X86_UP_APIC
625 bool "Local APIC support on uniprocessors"
626 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
627 help
628 A local APIC (Advanced Programmable Interrupt Controller) is an
629 integrated interrupt controller in the CPU. If you have a single-CPU
630 system which has a processor with a local APIC, you can say Y here to
631 enable and use it. If you say Y here even though your machine doesn't
632 have a local APIC, then the kernel will still run with no slowdown at
633 all. The local APIC supports CPU-generated self-interrupts (timer,
634 performance counters), and the NMI watchdog which detects hard
635 lockups.
637 config X86_UP_IOAPIC
638 bool "IO-APIC support on uniprocessors"
639 depends on X86_UP_APIC
640 help
641 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
642 SMP-capable replacement for PC-style interrupt controllers. Most
643 SMP systems and many recent uniprocessor systems have one.
645 If you have a single-CPU system with an IO-APIC, you can say Y here
646 to use it. If you say Y here even though your machine doesn't have
647 an IO-APIC, then the kernel will still run with no slowdown at all.
649 config X86_LOCAL_APIC
650 def_bool y
651 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
653 config X86_IO_APIC
654 def_bool y
655 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
657 config X86_VISWS_APIC
658 def_bool y
659 depends on X86_32 && X86_VISWS
661 config X86_MCE
662 bool "Machine Check Exception"
663 depends on !X86_VOYAGER
664 ---help---
665 Machine Check Exception support allows the processor to notify the
666 kernel if it detects a problem (e.g. overheating, component failure).
667 The action the kernel takes depends on the severity of the problem,
668 ranging from a warning message on the console, to halting the machine.
669 Your processor must be a Pentium or newer to support this - check the
670 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
671 have a design flaw which leads to false MCE events - hence MCE is
672 disabled on all P5 processors, unless explicitly enabled with "mce"
673 as a boot argument. Similarly, if MCE is built in and creates a
674 problem on some new non-standard machine, you can boot with "nomce"
675 to disable it. MCE support simply ignores non-MCE processors like
676 the 386 and 486, so nearly everyone can say Y here.
678 config X86_MCE_INTEL
679 def_bool y
680 prompt "Intel MCE features"
681 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
682 help
683 Additional support for intel specific MCE features such as
684 the thermal monitor.
686 config X86_MCE_AMD
687 def_bool y
688 prompt "AMD MCE features"
689 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
690 help
691 Additional support for AMD specific MCE features such as
692 the DRAM Error Threshold.
694 config X86_MCE_NONFATAL
695 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
696 depends on X86_32 && X86_MCE
697 help
698 Enabling this feature starts a timer that triggers every 5 seconds which
699 will look at the machine check registers to see if anything happened.
700 Non-fatal problems automatically get corrected (but still logged).
701 Disable this if you don't want to see these messages.
702 Seeing the messages this option prints out may be indicative of dying
703 or out-of-spec (ie, overclocked) hardware.
704 This option only does something on certain CPUs.
705 (AMD Athlon/Duron and Intel Pentium 4)
707 config X86_MCE_P4THERMAL
708 bool "check for P4 thermal throttling interrupt."
709 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
710 help
711 Enabling this feature will cause a message to be printed when the P4
712 enters thermal throttling.
714 config VM86
715 bool "Enable VM86 support" if EMBEDDED
716 default y
717 depends on X86_32
718 help
719 This option is required by programs like DOSEMU to run 16-bit legacy
720 code on X86 processors. It also may be needed by software like
721 XFree86 to initialize some video cards via BIOS. Disabling this
722 option saves about 6k.
724 config TOSHIBA
725 tristate "Toshiba Laptop support"
726 depends on X86_32
727 ---help---
728 This adds a driver to safely access the System Management Mode of
729 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
730 not work on models with a Phoenix BIOS. The System Management Mode
731 is used to set the BIOS and power saving options on Toshiba portables.
733 For information on utilities to make use of this driver see the
734 Toshiba Linux utilities web site at:
735 <http://www.buzzard.org.uk/toshiba/>.
737 Say Y if you intend to run this kernel on a Toshiba portable.
738 Say N otherwise.
740 config I8K
741 tristate "Dell laptop support"
742 ---help---
743 This adds a driver to safely access the System Management Mode
744 of the CPU on the Dell Inspiron 8000. The System Management Mode
745 is used to read cpu temperature and cooling fan status and to
746 control the fans on the I8K portables.
748 This driver has been tested only on the Inspiron 8000 but it may
749 also work with other Dell laptops. You can force loading on other
750 models by passing the parameter `force=1' to the module. Use at
751 your own risk.
753 For information on utilities to make use of this driver see the
754 I8K Linux utilities web site at:
755 <http://people.debian.org/~dz/i8k/>
757 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
758 Say N otherwise.
760 config X86_REBOOTFIXUPS
761 def_bool n
762 prompt "Enable X86 board specific fixups for reboot"
763 depends on X86_32 && X86
764 ---help---
765 This enables chipset and/or board specific fixups to be done
766 in order to get reboot to work correctly. This is only needed on
767 some combinations of hardware and BIOS. The symptom, for which
768 this config is intended, is when reboot ends with a stalled/hung
769 system.
771 Currently, the only fixup is for the Geode machines using
772 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
774 Say Y if you want to enable the fixup. Currently, it's safe to
775 enable this option even if you don't need it.
776 Say N otherwise.
778 config MICROCODE
779 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
780 select FW_LOADER
781 ---help---
782 If you say Y here, you will be able to update the microcode on
783 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
784 Pentium III, Pentium 4, Xeon etc. You will obviously need the
785 actual microcode binary data itself which is not shipped with the
786 Linux kernel.
788 For latest news and information on obtaining all the required
789 ingredients for this driver, check:
790 <http://www.urbanmyth.org/microcode/>.
792 To compile this driver as a module, choose M here: the
793 module will be called microcode.
795 config MICROCODE_OLD_INTERFACE
796 def_bool y
797 depends on MICROCODE
799 config X86_MSR
800 tristate "/dev/cpu/*/msr - Model-specific register support"
801 help
802 This device gives privileged processes access to the x86
803 Model-Specific Registers (MSRs). It is a character device with
804 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
805 MSR accesses are directed to a specific CPU on multi-processor
806 systems.
808 config X86_CPUID
809 tristate "/dev/cpu/*/cpuid - CPU information support"
810 help
811 This device gives processes access to the x86 CPUID instruction to
812 be executed on a specific processor. It is a character device
813 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
814 /dev/cpu/31/cpuid.
816 choice
817 prompt "High Memory Support"
818 default HIGHMEM4G if !X86_NUMAQ
819 default HIGHMEM64G if X86_NUMAQ
820 depends on X86_32
822 config NOHIGHMEM
823 bool "off"
824 depends on !X86_NUMAQ
825 ---help---
826 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
827 However, the address space of 32-bit x86 processors is only 4
828 Gigabytes large. That means that, if you have a large amount of
829 physical memory, not all of it can be "permanently mapped" by the
830 kernel. The physical memory that's not permanently mapped is called
831 "high memory".
833 If you are compiling a kernel which will never run on a machine with
834 more than 1 Gigabyte total physical RAM, answer "off" here (default
835 choice and suitable for most users). This will result in a "3GB/1GB"
836 split: 3GB are mapped so that each process sees a 3GB virtual memory
837 space and the remaining part of the 4GB virtual memory space is used
838 by the kernel to permanently map as much physical memory as
839 possible.
841 If the machine has between 1 and 4 Gigabytes physical RAM, then
842 answer "4GB" here.
844 If more than 4 Gigabytes is used then answer "64GB" here. This
845 selection turns Intel PAE (Physical Address Extension) mode on.
846 PAE implements 3-level paging on IA32 processors. PAE is fully
847 supported by Linux, PAE mode is implemented on all recent Intel
848 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
849 then the kernel will not boot on CPUs that don't support PAE!
851 The actual amount of total physical memory will either be
852 auto detected or can be forced by using a kernel command line option
853 such as "mem=256M". (Try "man bootparam" or see the documentation of
854 your boot loader (lilo or loadlin) about how to pass options to the
855 kernel at boot time.)
857 If unsure, say "off".
859 config HIGHMEM4G
860 bool "4GB"
861 depends on !X86_NUMAQ
862 help
863 Select this if you have a 32-bit processor and between 1 and 4
864 gigabytes of physical RAM.
866 config HIGHMEM64G
867 bool "64GB"
868 depends on !M386 && !M486
869 select X86_PAE
870 help
871 Select this if you have a 32-bit processor and more than 4
872 gigabytes of physical RAM.
874 endchoice
876 choice
877 depends on EXPERIMENTAL
878 prompt "Memory split" if EMBEDDED
879 default VMSPLIT_3G
880 depends on X86_32
881 help
882 Select the desired split between kernel and user memory.
884 If the address range available to the kernel is less than the
885 physical memory installed, the remaining memory will be available
886 as "high memory". Accessing high memory is a little more costly
887 than low memory, as it needs to be mapped into the kernel first.
888 Note that increasing the kernel address space limits the range
889 available to user programs, making the address space there
890 tighter. Selecting anything other than the default 3G/1G split
891 will also likely make your kernel incompatible with binary-only
892 kernel modules.
894 If you are not absolutely sure what you are doing, leave this
895 option alone!
897 config VMSPLIT_3G
898 bool "3G/1G user/kernel split"
899 config VMSPLIT_3G_OPT
900 depends on !X86_PAE
901 bool "3G/1G user/kernel split (for full 1G low memory)"
902 config VMSPLIT_2G
903 bool "2G/2G user/kernel split"
904 config VMSPLIT_2G_OPT
905 depends on !X86_PAE
906 bool "2G/2G user/kernel split (for full 2G low memory)"
907 config VMSPLIT_1G
908 bool "1G/3G user/kernel split"
909 endchoice
911 config PAGE_OFFSET
912 hex
913 default 0xB0000000 if VMSPLIT_3G_OPT
914 default 0x80000000 if VMSPLIT_2G
915 default 0x78000000 if VMSPLIT_2G_OPT
916 default 0x40000000 if VMSPLIT_1G
917 default 0xC0000000
918 depends on X86_32
920 config HIGHMEM
921 def_bool y
922 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
924 config X86_PAE
925 def_bool n
926 prompt "PAE (Physical Address Extension) Support"
927 depends on X86_32 && !HIGHMEM4G
928 select RESOURCES_64BIT
929 help
930 PAE is required for NX support, and furthermore enables
931 larger swapspace support for non-overcommit purposes. It
932 has the cost of more pagetable lookup overhead, and also
933 consumes more pagetable space per process.
935 # Common NUMA Features
936 config NUMA
937 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
938 depends on SMP
939 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
940 default n if X86_PC
941 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
942 help
943 Enable NUMA (Non Uniform Memory Access) support.
944 The kernel will try to allocate memory used by a CPU on the
945 local memory controller of the CPU and add some more
946 NUMA awareness to the kernel.
948 For 32-bit this is currently highly experimental and should be only
949 used for kernel development. It might also cause boot failures.
950 For 64-bit this is recommended on all multiprocessor Opteron systems.
951 If the system is EM64T, you should say N unless your system is
952 EM64T NUMA.
954 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
955 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
957 config K8_NUMA
958 def_bool y
959 prompt "Old style AMD Opteron NUMA detection"
960 depends on X86_64 && NUMA && PCI
961 help
962 Enable K8 NUMA node topology detection. You should say Y here if
963 you have a multi processor AMD K8 system. This uses an old
964 method to read the NUMA configuration directly from the builtin
965 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
966 instead, which also takes priority if both are compiled in.
968 config X86_64_ACPI_NUMA
969 def_bool y
970 prompt "ACPI NUMA detection"
971 depends on X86_64 && NUMA && ACPI && PCI
972 select ACPI_NUMA
973 help
974 Enable ACPI SRAT based node topology detection.
976 # Some NUMA nodes have memory ranges that span
977 # other nodes. Even though a pfn is valid and
978 # between a node's start and end pfns, it may not
979 # reside on that node. See memmap_init_zone()
980 # for details.
981 config NODES_SPAN_OTHER_NODES
982 def_bool y
983 depends on X86_64_ACPI_NUMA
985 config NUMA_EMU
986 bool "NUMA emulation"
987 depends on X86_64 && NUMA
988 help
989 Enable NUMA emulation. A flat machine will be split
990 into virtual nodes when booted with "numa=fake=N", where N is the
991 number of nodes. This is only useful for debugging.
993 config NODES_SHIFT
994 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
995 range 1 9 if X86_64
996 default "9" if MAXSMP
997 default "6" if X86_64
998 default "4" if X86_NUMAQ
999 default "3"
1000 depends on NEED_MULTIPLE_NODES
1001 help
1002 Specify the maximum number of NUMA Nodes available on the target
1003 system. Increases memory reserved to accomodate various tables.
1005 config HAVE_ARCH_BOOTMEM_NODE
1006 def_bool y
1007 depends on X86_32 && NUMA
1009 config ARCH_HAVE_MEMORY_PRESENT
1010 def_bool y
1011 depends on X86_32 && DISCONTIGMEM
1013 config NEED_NODE_MEMMAP_SIZE
1014 def_bool y
1015 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1017 config HAVE_ARCH_ALLOC_REMAP
1018 def_bool y
1019 depends on X86_32 && NUMA
1021 config ARCH_FLATMEM_ENABLE
1022 def_bool y
1023 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
1025 config ARCH_DISCONTIGMEM_ENABLE
1026 def_bool y
1027 depends on NUMA && X86_32
1029 config ARCH_DISCONTIGMEM_DEFAULT
1030 def_bool y
1031 depends on NUMA && X86_32
1033 config ARCH_SPARSEMEM_DEFAULT
1034 def_bool y
1035 depends on X86_64
1037 config ARCH_SPARSEMEM_ENABLE
1038 def_bool y
1039 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1040 select SPARSEMEM_STATIC if X86_32
1041 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1043 config ARCH_SELECT_MEMORY_MODEL
1044 def_bool y
1045 depends on ARCH_SPARSEMEM_ENABLE
1047 config ARCH_MEMORY_PROBE
1048 def_bool X86_64
1049 depends on MEMORY_HOTPLUG
1051 source "mm/Kconfig"
1053 config HIGHPTE
1054 bool "Allocate 3rd-level pagetables from highmem"
1055 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1056 help
1057 The VM uses one page table entry for each page of physical memory.
1058 For systems with a lot of RAM, this can be wasteful of precious
1059 low memory. Setting this option will put user-space page table
1060 entries in high memory.
1062 config MATH_EMULATION
1063 bool
1064 prompt "Math emulation" if X86_32
1065 ---help---
1066 Linux can emulate a math coprocessor (used for floating point
1067 operations) if you don't have one. 486DX and Pentium processors have
1068 a math coprocessor built in, 486SX and 386 do not, unless you added
1069 a 487DX or 387, respectively. (The messages during boot time can
1070 give you some hints here ["man dmesg"].) Everyone needs either a
1071 coprocessor or this emulation.
1073 If you don't have a math coprocessor, you need to say Y here; if you
1074 say Y here even though you have a coprocessor, the coprocessor will
1075 be used nevertheless. (This behavior can be changed with the kernel
1076 command line option "no387", which comes handy if your coprocessor
1077 is broken. Try "man bootparam" or see the documentation of your boot
1078 loader (lilo or loadlin) about how to pass options to the kernel at
1079 boot time.) This means that it is a good idea to say Y here if you
1080 intend to use this kernel on different machines.
1082 More information about the internals of the Linux math coprocessor
1083 emulation can be found in <file:arch/x86/math-emu/README>.
1085 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1086 kernel, it won't hurt.
1088 config MTRR
1089 bool "MTRR (Memory Type Range Register) support"
1090 ---help---
1091 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1092 the Memory Type Range Registers (MTRRs) may be used to control
1093 processor access to memory ranges. This is most useful if you have
1094 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1095 allows bus write transfers to be combined into a larger transfer
1096 before bursting over the PCI/AGP bus. This can increase performance
1097 of image write operations 2.5 times or more. Saying Y here creates a
1098 /proc/mtrr file which may be used to manipulate your processor's
1099 MTRRs. Typically the X server should use this.
1101 This code has a reasonably generic interface so that similar
1102 control registers on other processors can be easily supported
1103 as well:
1105 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1106 Registers (ARRs) which provide a similar functionality to MTRRs. For
1107 these, the ARRs are used to emulate the MTRRs.
1108 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1109 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1110 write-combining. All of these processors are supported by this code
1111 and it makes sense to say Y here if you have one of them.
1113 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1114 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1115 can lead to all sorts of problems, so it's good to say Y here.
1117 You can safely say Y even if your machine doesn't have MTRRs, you'll
1118 just add about 9 KB to your kernel.
1120 See <file:Documentation/mtrr.txt> for more information.
1122 config MTRR_SANITIZER
1123 bool
1124 prompt "MTRR cleanup support"
1125 depends on MTRR
1126 help
1127 Convert MTRR layout from continuous to discrete, so X drivers can
1128 add writeback entries.
1130 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1131 The largest mtrr entry size for a continous block can be set with
1132 mtrr_chunk_size.
1134 If unsure, say N.
1136 config MTRR_SANITIZER_ENABLE_DEFAULT
1137 int "MTRR cleanup enable value (0-1)"
1138 range 0 1
1139 default "0"
1140 depends on MTRR_SANITIZER
1141 help
1142 Enable mtrr cleanup default value
1144 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1145 int "MTRR cleanup spare reg num (0-7)"
1146 range 0 7
1147 default "1"
1148 depends on MTRR_SANITIZER
1149 help
1150 mtrr cleanup spare entries default, it can be changed via
1151 mtrr_spare_reg_nr=N on the kernel command line.
1153 config X86_PAT
1154 bool
1155 prompt "x86 PAT support"
1156 depends on MTRR
1157 help
1158 Use PAT attributes to setup page level cache control.
1160 PATs are the modern equivalents of MTRRs and are much more
1161 flexible than MTRRs.
1163 Say N here if you see bootup problems (boot crash, boot hang,
1164 spontaneous reboots) or a non-working video driver.
1166 If unsure, say Y.
1168 config EFI
1169 def_bool n
1170 prompt "EFI runtime service support"
1171 depends on ACPI
1172 ---help---
1173 This enables the kernel to use EFI runtime services that are
1174 available (such as the EFI variable services).
1176 This option is only useful on systems that have EFI firmware.
1177 In addition, you should use the latest ELILO loader available
1178 at <http://elilo.sourceforge.net> in order to take advantage
1179 of EFI runtime services. However, even with this option, the
1180 resultant kernel should continue to boot on existing non-EFI
1181 platforms.
1183 config IRQBALANCE
1184 def_bool y
1185 prompt "Enable kernel irq balancing"
1186 depends on X86_32 && SMP && X86_IO_APIC
1187 help
1188 The default yes will allow the kernel to do irq load balancing.
1189 Saying no will keep the kernel from doing irq load balancing.
1191 config SECCOMP
1192 def_bool y
1193 prompt "Enable seccomp to safely compute untrusted bytecode"
1194 depends on PROC_FS
1195 help
1196 This kernel feature is useful for number crunching applications
1197 that may need to compute untrusted bytecode during their
1198 execution. By using pipes or other transports made available to
1199 the process as file descriptors supporting the read/write
1200 syscalls, it's possible to isolate those applications in
1201 their own address space using seccomp. Once seccomp is
1202 enabled via /proc/<pid>/seccomp, it cannot be disabled
1203 and the task is only allowed to execute a few safe syscalls
1204 defined by each seccomp mode.
1206 If unsure, say Y. Only embedded should say N here.
1208 config CC_STACKPROTECTOR
1209 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1210 depends on X86_64 && EXPERIMENTAL && BROKEN
1211 help
1212 This option turns on the -fstack-protector GCC feature. This
1213 feature puts, at the beginning of critical functions, a canary
1214 value on the stack just before the return address, and validates
1215 the value just before actually returning. Stack based buffer
1216 overflows (that need to overwrite this return address) now also
1217 overwrite the canary, which gets detected and the attack is then
1218 neutralized via a kernel panic.
1220 This feature requires gcc version 4.2 or above, or a distribution
1221 gcc with the feature backported. Older versions are automatically
1222 detected and for those versions, this configuration option is ignored.
1224 config CC_STACKPROTECTOR_ALL
1225 bool "Use stack-protector for all functions"
1226 depends on CC_STACKPROTECTOR
1227 help
1228 Normally, GCC only inserts the canary value protection for
1229 functions that use large-ish on-stack buffers. By enabling
1230 this option, GCC will be asked to do this for ALL functions.
1232 source kernel/Kconfig.hz
1234 config KEXEC
1235 bool "kexec system call"
1236 depends on X86_BIOS_REBOOT
1237 help
1238 kexec is a system call that implements the ability to shutdown your
1239 current kernel, and to start another kernel. It is like a reboot
1240 but it is independent of the system firmware. And like a reboot
1241 you can start any kernel with it, not just Linux.
1243 The name comes from the similarity to the exec system call.
1245 It is an ongoing process to be certain the hardware in a machine
1246 is properly shutdown, so do not be surprised if this code does not
1247 initially work for you. It may help to enable device hotplugging
1248 support. As of this writing the exact hardware interface is
1249 strongly in flux, so no good recommendation can be made.
1251 config CRASH_DUMP
1252 bool "kernel crash dumps"
1253 depends on X86_64 || (X86_32 && HIGHMEM)
1254 help
1255 Generate crash dump after being started by kexec.
1256 This should be normally only set in special crash dump kernels
1257 which are loaded in the main kernel with kexec-tools into
1258 a specially reserved region and then later executed after
1259 a crash by kdump/kexec. The crash dump kernel must be compiled
1260 to a memory address not used by the main kernel or BIOS using
1261 PHYSICAL_START, or it must be built as a relocatable image
1262 (CONFIG_RELOCATABLE=y).
1263 For more details see Documentation/kdump/kdump.txt
1265 config KEXEC_JUMP
1266 bool "kexec jump (EXPERIMENTAL)"
1267 depends on EXPERIMENTAL
1268 depends on KEXEC && HIBERNATION && X86_32
1269 help
1270 Jump between original kernel and kexeced kernel and invoke
1271 code in physical address mode via KEXEC
1273 config PHYSICAL_START
1274 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1275 default "0x1000000" if X86_NUMAQ
1276 default "0x200000" if X86_64
1277 default "0x100000"
1278 help
1279 This gives the physical address where the kernel is loaded.
1281 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1282 bzImage will decompress itself to above physical address and
1283 run from there. Otherwise, bzImage will run from the address where
1284 it has been loaded by the boot loader and will ignore above physical
1285 address.
1287 In normal kdump cases one does not have to set/change this option
1288 as now bzImage can be compiled as a completely relocatable image
1289 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1290 address. This option is mainly useful for the folks who don't want
1291 to use a bzImage for capturing the crash dump and want to use a
1292 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1293 to be specifically compiled to run from a specific memory area
1294 (normally a reserved region) and this option comes handy.
1296 So if you are using bzImage for capturing the crash dump, leave
1297 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1298 Otherwise if you plan to use vmlinux for capturing the crash dump
1299 change this value to start of the reserved region (Typically 16MB
1300 0x1000000). In other words, it can be set based on the "X" value as
1301 specified in the "crashkernel=YM@XM" command line boot parameter
1302 passed to the panic-ed kernel. Typically this parameter is set as
1303 crashkernel=64M@16M. Please take a look at
1304 Documentation/kdump/kdump.txt for more details about crash dumps.
1306 Usage of bzImage for capturing the crash dump is recommended as
1307 one does not have to build two kernels. Same kernel can be used
1308 as production kernel and capture kernel. Above option should have
1309 gone away after relocatable bzImage support is introduced. But it
1310 is present because there are users out there who continue to use
1311 vmlinux for dump capture. This option should go away down the
1312 line.
1314 Don't change this unless you know what you are doing.
1316 config RELOCATABLE
1317 bool "Build a relocatable kernel (EXPERIMENTAL)"
1318 depends on EXPERIMENTAL
1319 help
1320 This builds a kernel image that retains relocation information
1321 so it can be loaded someplace besides the default 1MB.
1322 The relocations tend to make the kernel binary about 10% larger,
1323 but are discarded at runtime.
1325 One use is for the kexec on panic case where the recovery kernel
1326 must live at a different physical address than the primary
1327 kernel.
1329 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1330 it has been loaded at and the compile time physical address
1331 (CONFIG_PHYSICAL_START) is ignored.
1333 config PHYSICAL_ALIGN
1334 hex
1335 prompt "Alignment value to which kernel should be aligned" if X86_32
1336 default "0x100000" if X86_32
1337 default "0x200000" if X86_64
1338 range 0x2000 0x400000
1339 help
1340 This value puts the alignment restrictions on physical address
1341 where kernel is loaded and run from. Kernel is compiled for an
1342 address which meets above alignment restriction.
1344 If bootloader loads the kernel at a non-aligned address and
1345 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1346 address aligned to above value and run from there.
1348 If bootloader loads the kernel at a non-aligned address and
1349 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1350 load address and decompress itself to the address it has been
1351 compiled for and run from there. The address for which kernel is
1352 compiled already meets above alignment restrictions. Hence the
1353 end result is that kernel runs from a physical address meeting
1354 above alignment restrictions.
1356 Don't change this unless you know what you are doing.
1358 config HOTPLUG_CPU
1359 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1360 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1361 ---help---
1362 Say Y here to experiment with turning CPUs off and on, and to
1363 enable suspend on SMP systems. CPUs can be controlled through
1364 /sys/devices/system/cpu.
1365 Say N if you want to disable CPU hotplug and don't need to
1366 suspend.
1368 config COMPAT_VDSO
1369 def_bool y
1370 prompt "Compat VDSO support"
1371 depends on X86_32 || IA32_EMULATION
1372 help
1373 Map the 32-bit VDSO to the predictable old-style address too.
1374 ---help---
1375 Say N here if you are running a sufficiently recent glibc
1376 version (2.3.3 or later), to remove the high-mapped
1377 VDSO mapping and to exclusively use the randomized VDSO.
1379 If unsure, say Y.
1381 endmenu
1383 config ARCH_ENABLE_MEMORY_HOTPLUG
1384 def_bool y
1385 depends on X86_64 || (X86_32 && HIGHMEM)
1387 config HAVE_ARCH_EARLY_PFN_TO_NID
1388 def_bool X86_64
1389 depends on NUMA
1391 menu "Power management options"
1392 depends on !X86_VOYAGER
1394 config ARCH_HIBERNATION_HEADER
1395 def_bool y
1396 depends on X86_64 && HIBERNATION
1398 source "kernel/power/Kconfig"
1400 source "drivers/acpi/Kconfig"
1402 config X86_APM_BOOT
1403 bool
1404 default y
1405 depends on APM || APM_MODULE
1407 menuconfig APM
1408 tristate "APM (Advanced Power Management) BIOS support"
1409 depends on X86_32 && PM_SLEEP
1410 ---help---
1411 APM is a BIOS specification for saving power using several different
1412 techniques. This is mostly useful for battery powered laptops with
1413 APM compliant BIOSes. If you say Y here, the system time will be
1414 reset after a RESUME operation, the /proc/apm device will provide
1415 battery status information, and user-space programs will receive
1416 notification of APM "events" (e.g. battery status change).
1418 If you select "Y" here, you can disable actual use of the APM
1419 BIOS by passing the "apm=off" option to the kernel at boot time.
1421 Note that the APM support is almost completely disabled for
1422 machines with more than one CPU.
1424 In order to use APM, you will need supporting software. For location
1425 and more information, read <file:Documentation/power/pm.txt> and the
1426 Battery Powered Linux mini-HOWTO, available from
1427 <http://www.tldp.org/docs.html#howto>.
1429 This driver does not spin down disk drives (see the hdparm(8)
1430 manpage ("man 8 hdparm") for that), and it doesn't turn off
1431 VESA-compliant "green" monitors.
1433 This driver does not support the TI 4000M TravelMate and the ACER
1434 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1435 desktop machines also don't have compliant BIOSes, and this driver
1436 may cause those machines to panic during the boot phase.
1438 Generally, if you don't have a battery in your machine, there isn't
1439 much point in using this driver and you should say N. If you get
1440 random kernel OOPSes or reboots that don't seem to be related to
1441 anything, try disabling/enabling this option (or disabling/enabling
1442 APM in your BIOS).
1444 Some other things you should try when experiencing seemingly random,
1445 "weird" problems:
1447 1) make sure that you have enough swap space and that it is
1448 enabled.
1449 2) pass the "no-hlt" option to the kernel
1450 3) switch on floating point emulation in the kernel and pass
1451 the "no387" option to the kernel
1452 4) pass the "floppy=nodma" option to the kernel
1453 5) pass the "mem=4M" option to the kernel (thereby disabling
1454 all but the first 4 MB of RAM)
1455 6) make sure that the CPU is not over clocked.
1456 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1457 8) disable the cache from your BIOS settings
1458 9) install a fan for the video card or exchange video RAM
1459 10) install a better fan for the CPU
1460 11) exchange RAM chips
1461 12) exchange the motherboard.
1463 To compile this driver as a module, choose M here: the
1464 module will be called apm.
1466 if APM
1468 config APM_IGNORE_USER_SUSPEND
1469 bool "Ignore USER SUSPEND"
1470 help
1471 This option will ignore USER SUSPEND requests. On machines with a
1472 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1473 series notebooks, it is necessary to say Y because of a BIOS bug.
1475 config APM_DO_ENABLE
1476 bool "Enable PM at boot time"
1477 ---help---
1478 Enable APM features at boot time. From page 36 of the APM BIOS
1479 specification: "When disabled, the APM BIOS does not automatically
1480 power manage devices, enter the Standby State, enter the Suspend
1481 State, or take power saving steps in response to CPU Idle calls."
1482 This driver will make CPU Idle calls when Linux is idle (unless this
1483 feature is turned off -- see "Do CPU IDLE calls", below). This
1484 should always save battery power, but more complicated APM features
1485 will be dependent on your BIOS implementation. You may need to turn
1486 this option off if your computer hangs at boot time when using APM
1487 support, or if it beeps continuously instead of suspending. Turn
1488 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1489 T400CDT. This is off by default since most machines do fine without
1490 this feature.
1492 config APM_CPU_IDLE
1493 bool "Make CPU Idle calls when idle"
1494 help
1495 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1496 On some machines, this can activate improved power savings, such as
1497 a slowed CPU clock rate, when the machine is idle. These idle calls
1498 are made after the idle loop has run for some length of time (e.g.,
1499 333 mS). On some machines, this will cause a hang at boot time or
1500 whenever the CPU becomes idle. (On machines with more than one CPU,
1501 this option does nothing.)
1503 config APM_DISPLAY_BLANK
1504 bool "Enable console blanking using APM"
1505 help
1506 Enable console blanking using the APM. Some laptops can use this to
1507 turn off the LCD backlight when the screen blanker of the Linux
1508 virtual console blanks the screen. Note that this is only used by
1509 the virtual console screen blanker, and won't turn off the backlight
1510 when using the X Window system. This also doesn't have anything to
1511 do with your VESA-compliant power-saving monitor. Further, this
1512 option doesn't work for all laptops -- it might not turn off your
1513 backlight at all, or it might print a lot of errors to the console,
1514 especially if you are using gpm.
1516 config APM_ALLOW_INTS
1517 bool "Allow interrupts during APM BIOS calls"
1518 help
1519 Normally we disable external interrupts while we are making calls to
1520 the APM BIOS as a measure to lessen the effects of a badly behaving
1521 BIOS implementation. The BIOS should reenable interrupts if it
1522 needs to. Unfortunately, some BIOSes do not -- especially those in
1523 many of the newer IBM Thinkpads. If you experience hangs when you
1524 suspend, try setting this to Y. Otherwise, say N.
1526 config APM_REAL_MODE_POWER_OFF
1527 bool "Use real mode APM BIOS call to power off"
1528 help
1529 Use real mode APM BIOS calls to switch off the computer. This is
1530 a work-around for a number of buggy BIOSes. Switch this option on if
1531 your computer crashes instead of powering off properly.
1533 endif # APM
1535 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1537 source "drivers/cpuidle/Kconfig"
1539 endmenu
1542 menu "Bus options (PCI etc.)"
1544 config PCI
1545 bool "PCI support"
1546 default y
1547 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1548 help
1549 Find out whether you have a PCI motherboard. PCI is the name of a
1550 bus system, i.e. the way the CPU talks to the other stuff inside
1551 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1552 VESA. If you have PCI, say Y, otherwise N.
1554 choice
1555 prompt "PCI access mode"
1556 depends on X86_32 && PCI
1557 default PCI_GOANY
1558 ---help---
1559 On PCI systems, the BIOS can be used to detect the PCI devices and
1560 determine their configuration. However, some old PCI motherboards
1561 have BIOS bugs and may crash if this is done. Also, some embedded
1562 PCI-based systems don't have any BIOS at all. Linux can also try to
1563 detect the PCI hardware directly without using the BIOS.
1565 With this option, you can specify how Linux should detect the
1566 PCI devices. If you choose "BIOS", the BIOS will be used,
1567 if you choose "Direct", the BIOS won't be used, and if you
1568 choose "MMConfig", then PCI Express MMCONFIG will be used.
1569 If you choose "Any", the kernel will try MMCONFIG, then the
1570 direct access method and falls back to the BIOS if that doesn't
1571 work. If unsure, go with the default, which is "Any".
1573 config PCI_GOBIOS
1574 bool "BIOS"
1576 config PCI_GOMMCONFIG
1577 bool "MMConfig"
1579 config PCI_GODIRECT
1580 bool "Direct"
1582 config PCI_GOOLPC
1583 bool "OLPC"
1584 depends on OLPC
1586 config PCI_GOANY
1587 bool "Any"
1589 endchoice
1591 config PCI_BIOS
1592 def_bool y
1593 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1595 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1596 config PCI_DIRECT
1597 def_bool y
1598 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1600 config PCI_MMCONFIG
1601 def_bool y
1602 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1604 config PCI_OLPC
1605 def_bool y
1606 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1608 config PCI_DOMAINS
1609 def_bool y
1610 depends on PCI
1612 config PCI_MMCONFIG
1613 bool "Support mmconfig PCI config space access"
1614 depends on X86_64 && PCI && ACPI
1616 config DMAR
1617 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1618 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1619 help
1620 DMA remapping (DMAR) devices support enables independent address
1621 translations for Direct Memory Access (DMA) from devices.
1622 These DMA remapping devices are reported via ACPI tables
1623 and include PCI device scope covered by these DMA
1624 remapping devices.
1626 config DMAR_GFX_WA
1627 def_bool y
1628 prompt "Support for Graphics workaround"
1629 depends on DMAR
1630 help
1631 Current Graphics drivers tend to use physical address
1632 for DMA and avoid using DMA APIs. Setting this config
1633 option permits the IOMMU driver to set a unity map for
1634 all the OS-visible memory. Hence the driver can continue
1635 to use physical addresses for DMA.
1637 config DMAR_FLOPPY_WA
1638 def_bool y
1639 depends on DMAR
1640 help
1641 Floppy disk drivers are know to bypass DMA API calls
1642 thereby failing to work when IOMMU is enabled. This
1643 workaround will setup a 1:1 mapping for the first
1644 16M to make floppy (an ISA device) work.
1646 source "drivers/pci/pcie/Kconfig"
1648 source "drivers/pci/Kconfig"
1650 # x86_64 have no ISA slots, but do have ISA-style DMA.
1651 config ISA_DMA_API
1652 def_bool y
1654 if X86_32
1656 config ISA
1657 bool "ISA support"
1658 depends on !X86_VOYAGER
1659 help
1660 Find out whether you have ISA slots on your motherboard. ISA is the
1661 name of a bus system, i.e. the way the CPU talks to the other stuff
1662 inside your box. Other bus systems are PCI, EISA, MicroChannel
1663 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1664 newer boards don't support it. If you have ISA, say Y, otherwise N.
1666 config EISA
1667 bool "EISA support"
1668 depends on ISA
1669 ---help---
1670 The Extended Industry Standard Architecture (EISA) bus was
1671 developed as an open alternative to the IBM MicroChannel bus.
1673 The EISA bus provided some of the features of the IBM MicroChannel
1674 bus while maintaining backward compatibility with cards made for
1675 the older ISA bus. The EISA bus saw limited use between 1988 and
1676 1995 when it was made obsolete by the PCI bus.
1678 Say Y here if you are building a kernel for an EISA-based machine.
1680 Otherwise, say N.
1682 source "drivers/eisa/Kconfig"
1684 config MCA
1685 bool "MCA support" if !X86_VOYAGER
1686 default y if X86_VOYAGER
1687 help
1688 MicroChannel Architecture is found in some IBM PS/2 machines and
1689 laptops. It is a bus system similar to PCI or ISA. See
1690 <file:Documentation/mca.txt> (and especially the web page given
1691 there) before attempting to build an MCA bus kernel.
1693 source "drivers/mca/Kconfig"
1695 config SCx200
1696 tristate "NatSemi SCx200 support"
1697 depends on !X86_VOYAGER
1698 help
1699 This provides basic support for National Semiconductor's
1700 (now AMD's) Geode processors. The driver probes for the
1701 PCI-IDs of several on-chip devices, so its a good dependency
1702 for other scx200_* drivers.
1704 If compiled as a module, the driver is named scx200.
1706 config SCx200HR_TIMER
1707 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1708 depends on SCx200 && GENERIC_TIME
1709 default y
1710 help
1711 This driver provides a clocksource built upon the on-chip
1712 27MHz high-resolution timer. Its also a workaround for
1713 NSC Geode SC-1100's buggy TSC, which loses time when the
1714 processor goes idle (as is done by the scheduler). The
1715 other workaround is idle=poll boot option.
1717 config GEODE_MFGPT_TIMER
1718 def_bool y
1719 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1720 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1721 help
1722 This driver provides a clock event source based on the MFGPT
1723 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1724 MFGPTs have a better resolution and max interval than the
1725 generic PIT, and are suitable for use as high-res timers.
1727 config OLPC
1728 bool "One Laptop Per Child support"
1729 default n
1730 help
1731 Add support for detecting the unique features of the OLPC
1732 XO hardware.
1734 endif # X86_32
1736 config K8_NB
1737 def_bool y
1738 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1740 source "drivers/pcmcia/Kconfig"
1742 source "drivers/pci/hotplug/Kconfig"
1744 endmenu
1747 menu "Executable file formats / Emulations"
1749 source "fs/Kconfig.binfmt"
1751 config IA32_EMULATION
1752 bool "IA32 Emulation"
1753 depends on X86_64
1754 select COMPAT_BINFMT_ELF
1755 help
1756 Include code to run 32-bit programs under a 64-bit kernel. You should
1757 likely turn this on, unless you're 100% sure that you don't have any
1758 32-bit programs left.
1760 config IA32_AOUT
1761 tristate "IA32 a.out support"
1762 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1763 help
1764 Support old a.out binaries in the 32bit emulation.
1766 config COMPAT
1767 def_bool y
1768 depends on IA32_EMULATION
1770 config COMPAT_FOR_U64_ALIGNMENT
1771 def_bool COMPAT
1772 depends on X86_64
1774 config SYSVIPC_COMPAT
1775 def_bool y
1776 depends on X86_64 && COMPAT && SYSVIPC
1778 endmenu
1781 source "net/Kconfig"
1783 source "drivers/Kconfig"
1785 source "drivers/firmware/Kconfig"
1787 source "fs/Kconfig"
1789 source "arch/x86/Kconfig.debug"
1791 source "security/Kconfig"
1793 source "crypto/Kconfig"
1795 source "arch/x86/kvm/Kconfig"
1797 source "lib/Kconfig"