15 config GENERIC_CMOS_UPDATE
19 config CLOCKSOURCE_WATCHDOG
23 config GENERIC_CLOCKEVENTS
27 config GENERIC_CLOCKEVENTS_BROADCAST
30 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
32 config LOCKDEP_SUPPORT
36 config STACKTRACE_SUPPORT
40 config SEMAPHORE_SLEEPERS
59 config GENERIC_ISA_DMA
72 config GENERIC_HWEIGHT
76 config ARCH_MAY_HAVE_PC_FDC
84 config RWSEM_GENERIC_SPINLOCK
87 config RWSEM_XCHGADD_ALGORITHM
90 config ARCH_HAS_ILOG2_U32
93 config ARCH_HAS_ILOG2_U64
96 config GENERIC_CALIBRATE_DELAY
99 config GENERIC_TIME_VSYSCALL
111 config ARCH_POPULATES_NODE_MAP
118 # Use the generic interrupt handling code in kernel/irq/:
119 config GENERIC_HARDIRQS
123 config GENERIC_IRQ_PROBE
127 config GENERIC_PENDING_IRQ
129 depends on GENERIC_HARDIRQS && SMP
134 depends on X86_32 && SMP && !X86_VOYAGER
139 depends on SMP && !(X86_VISWS || X86_VOYAGER || MK8)
142 config X86_BIOS_REBOOT
144 depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
147 config X86_TRAMPOLINE
149 depends on X86_SMP || (X86_VOYAGER && SMP)
154 source "init/Kconfig"
156 menu "Processor type and features"
158 source "kernel/time/Kconfig"
161 bool "Symmetric multi-processing support"
163 This enables support for systems with more than one CPU. If you have
164 a system with only one CPU, like most personal computers, say N. If
165 you have a system with more than one CPU, say Y.
167 If you say N here, the kernel will run on single and multiprocessor
168 machines, but will use only one CPU of a multiprocessor machine. If
169 you say Y here, the kernel will run on many, but not all,
170 singleprocessor machines. On a singleprocessor machine, the kernel
171 will run faster if you say N here.
173 Note that if you say Y here and choose architecture "586" or
174 "Pentium" under "Processor family", the kernel will not work on 486
175 architectures. Similarly, multiprocessor kernels for the "PPro"
176 architecture may not work on all Pentium based boards.
178 People using multiprocessor machines who say Y here should also say
179 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
180 Management" code will be disabled if you say Y here.
182 See also the <file:Documentation/smp.txt>,
183 <file:Documentation/i386/IO-APIC.txt>,
184 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
185 <http://www.tldp.org/docs.html#howto>.
187 If you don't know what to do here, say N.
190 prompt "Subarchitecture Type"
196 Choose this option if your computer is a standard PC or compatible.
202 Select this for an AMD Elan processor.
204 Do not use this option for K6/Athlon/Opteron processors!
206 If unsure, choose "PC-compatible" instead.
211 select SMP if !BROKEN
213 Voyager is an MCA-based 32-way capable SMP architecture proprietary
214 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
218 If you do not specifically know you have a Voyager based machine,
219 say N here, otherwise the kernel you build will not be bootable.
222 bool "NUMAQ (IBM/Sequent)"
227 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
228 multiquad box. This changes the way that processors are bootstrapped,
229 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
230 You will need a new lynxer.elf file to flash your firmware with - send
231 email to <Martin.Bligh@us.ibm.com>.
234 bool "Summit/EXA (IBM x440)"
235 depends on X86_32 && SMP
237 This option is needed for IBM systems that use the Summit/EXA chipset.
238 In particular, it is needed for the x440.
240 If you don't have one of these computers, you should say N here.
241 If you want to build a NUMA kernel, you must select ACPI.
244 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
245 depends on X86_32 && SMP
247 This option is needed for the systems that have more than 8 CPUs
248 and if the system is not of any sub-arch type above.
250 If you don't have such a system, you should say N here.
253 bool "SGI 320/540 (Visual Workstation)"
256 The SGI Visual Workstation series is an IA32-based workstation
257 based on SGI systems chips with some legacy PC hardware attached.
259 Say Y here to create a kernel to run on the SGI 320 or 540.
261 A kernel compiled for the Visual Workstation will not run on PCs
262 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
264 config X86_GENERICARCH
265 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
268 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
269 It is intended for a generic binary kernel.
270 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
273 bool "Support for Unisys ES7000 IA32 series"
274 depends on X86_32 && SMP
276 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
277 supposed to run on an IA32-based Unisys ES7000 system.
278 Only choose this option if you have such a system, otherwise you
282 bool "Support for ScaleMP vSMP"
283 depends on X86_64 && PCI
285 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
286 supposed to run on these EM64T-based machines. Only choose this option
287 if you have one of these machines.
291 config SCHED_NO_NO_OMIT_FRAME_POINTER
292 bool "Single-depth WCHAN output"
296 Calculate simpler /proc/<PID>/wchan values. If this option
297 is disabled then wchan values will recurse back to the
298 caller function. This provides more accurate wchan values,
299 at the expense of slightly more scheduling overhead.
301 If in doubt, say "Y".
305 depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
307 This changes the kernel so it can modify itself when it is run
308 under a hypervisor, potentially improving performance significantly
309 over full virtualization. However, when run without a hypervisor
310 the kernel is theoretically slower and slightly larger.
312 menuconfig PARAVIRT_GUEST
313 bool "Paravirtualized guest support"
316 Say Y here to get to see options related to running Linux under
317 various hypervisors. This option alone does not add any kernel code.
319 If you say N, all options in this submenu will be skipped and disabled.
323 source "arch/x86/xen/Kconfig"
326 bool "VMI Guest support"
328 depends on !(X86_VISWS || X86_VOYAGER)
330 VMI provides a paravirtualized interface to the VMware ESX server
331 (it could be used by other hypervisors in theory too, but is not
332 at the moment), by linking the kernel to a GPL-ed ROM module
333 provided by the hypervisor.
335 source "arch/x86/lguest/Kconfig"
342 depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
345 config HAVE_ARCH_PARSE_SRAT
350 config X86_SUMMIT_NUMA
353 depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
355 config X86_CYCLONE_TIMER
358 depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
360 config ES7000_CLUSTERED_APIC
363 depends on SMP && X86_ES7000 && MPENTIUMIII
365 source "arch/x86/Kconfig.cpu"
369 prompt "HPET Timer Support" if X86_32
372 Use the IA-PC HPET (High Precision Event Timer) to manage
373 time in preference to the PIT and RTC, if a HPET is
375 HPET is the next generation timer replacing legacy 8254s.
376 The HPET provides a stable time base on SMP
377 systems, unlike the TSC, but it is more expensive to access,
378 as it is off-chip. You can find the HPET spec at
379 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
381 You can safely choose Y here. However, HPET will only be
382 activated if the platform and the BIOS support this feature.
383 Otherwise the 8254 will be used for timing services.
385 Choose N to continue using the legacy 8254 timer.
387 config HPET_EMULATE_RTC
389 depends on HPET_TIMER && RTC=y
392 # Mark as embedded because too many people got it wrong.
393 # The code disables itself when not needed.
395 bool "GART IOMMU support" if EMBEDDED
399 depends on X86_64 && PCI
401 Support for full DMA access of devices with 32bit memory access only
402 on systems with more than 3GB. This is usually needed for USB,
403 sound, many IDE/SATA chipsets and some other devices.
404 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
405 based hardware IOMMU and a software bounce buffer based IOMMU used
406 on Intel systems and as fallback.
407 The code is only active when needed (enough memory and limited
408 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
412 bool "IBM Calgary IOMMU support"
414 depends on X86_64 && PCI && EXPERIMENTAL
416 Support for hardware IOMMUs in IBM's xSeries x366 and x460
417 systems. Needed to run systems with more than 3GB of memory
418 properly with 32-bit PCI devices that do not support DAC
419 (Double Address Cycle). Calgary also supports bus level
420 isolation, where all DMAs pass through the IOMMU. This
421 prevents them from going anywhere except their intended
422 destination. This catches hard-to-find kernel bugs and
423 mis-behaving drivers and devices that do not use the DMA-API
424 properly to set up their DMA buffers. The IOMMU can be
425 turned off at boot time with the iommu=off parameter.
426 Normally the kernel will make the right choice by itself.
429 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
430 bool "Should Calgary be enabled by default?"
432 depends on CALGARY_IOMMU
434 Should Calgary be enabled by default? if you choose 'y', Calgary
435 will be used (if it exists). If you choose 'n', Calgary will not be
436 used even if it exists. If you choose 'n' and would like to use
437 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
440 # need this always selected by IOMMU for the VIA workaround
444 Support for software bounce buffers used on x86-64 systems
445 which don't have a hardware IOMMU (e.g. the current generation
446 of Intel's x86-64 CPUs). Using this PCI devices which can only
447 access 32-bits of memory can be used on systems with more than
448 3 GB of memory. If unsure, say Y.
452 int "Maximum number of CPUs (2-255)"
455 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
458 This allows you to specify the maximum number of CPUs which this
459 kernel will support. The maximum supported value is 255 and the
460 minimum value which makes sense is 2.
462 This is purely to save memory - each supported CPU adds
463 approximately eight kilobytes to the kernel image.
466 bool "SMT (Hyperthreading) scheduler support"
467 depends on (X86_64 && SMP) || (X86_32 && X86_HT)
469 SMT scheduler support improves the CPU scheduler's decision making
470 when dealing with Intel Pentium 4 chips with HyperThreading at a
471 cost of slightly increased overhead in some places. If unsure say
475 bool "Multi-core scheduler support"
476 depends on (X86_64 && SMP) || (X86_32 && X86_HT)
479 Multi-core scheduler support improves the CPU scheduler's decision
480 making when dealing with multi-core CPU chips at a cost of slightly
481 increased overhead in some places. If unsure say N here.
483 source "kernel/Kconfig.preempt"
486 bool "Local APIC support on uniprocessors"
487 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
489 A local APIC (Advanced Programmable Interrupt Controller) is an
490 integrated interrupt controller in the CPU. If you have a single-CPU
491 system which has a processor with a local APIC, you can say Y here to
492 enable and use it. If you say Y here even though your machine doesn't
493 have a local APIC, then the kernel will still run with no slowdown at
494 all. The local APIC supports CPU-generated self-interrupts (timer,
495 performance counters), and the NMI watchdog which detects hard
499 bool "IO-APIC support on uniprocessors"
500 depends on X86_UP_APIC
502 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
503 SMP-capable replacement for PC-style interrupt controllers. Most
504 SMP systems and many recent uniprocessor systems have one.
506 If you have a single-CPU system with an IO-APIC, you can say Y here
507 to use it. If you say Y here even though your machine doesn't have
508 an IO-APIC, then the kernel will still run with no slowdown at all.
510 config X86_LOCAL_APIC
512 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
517 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
520 config X86_VISWS_APIC
522 depends on X86_32 && X86_VISWS
526 bool "Machine Check Exception"
527 depends on !X86_VOYAGER
529 Machine Check Exception support allows the processor to notify the
530 kernel if it detects a problem (e.g. overheating, component failure).
531 The action the kernel takes depends on the severity of the problem,
532 ranging from a warning message on the console, to halting the machine.
533 Your processor must be a Pentium or newer to support this - check the
534 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
535 have a design flaw which leads to false MCE events - hence MCE is
536 disabled on all P5 processors, unless explicitly enabled with "mce"
537 as a boot argument. Similarly, if MCE is built in and creates a
538 problem on some new non-standard machine, you can boot with "nomce"
539 to disable it. MCE support simply ignores non-MCE processors like
540 the 386 and 486, so nearly everyone can say Y here.
543 bool "Intel MCE features"
544 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
547 Additional support for intel specific MCE features such as
551 bool "AMD MCE features"
552 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
555 Additional support for AMD specific MCE features such as
556 the DRAM Error Threshold.
558 config X86_MCE_NONFATAL
559 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
560 depends on X86_32 && X86_MCE
562 Enabling this feature starts a timer that triggers every 5 seconds which
563 will look at the machine check registers to see if anything happened.
564 Non-fatal problems automatically get corrected (but still logged).
565 Disable this if you don't want to see these messages.
566 Seeing the messages this option prints out may be indicative of dying
567 or out-of-spec (ie, overclocked) hardware.
568 This option only does something on certain CPUs.
569 (AMD Athlon/Duron and Intel Pentium 4)
571 config X86_MCE_P4THERMAL
572 bool "check for P4 thermal throttling interrupt."
573 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
575 Enabling this feature will cause a message to be printed when the P4
576 enters thermal throttling.
579 bool "Enable VM86 support" if EMBEDDED
583 This option is required by programs like DOSEMU to run 16-bit legacy
584 code on X86 processors. It also may be needed by software like
585 XFree86 to initialize some video cards via BIOS. Disabling this
586 option saves about 6k.
589 tristate "Toshiba Laptop support"
592 This adds a driver to safely access the System Management Mode of
593 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
594 not work on models with a Phoenix BIOS. The System Management Mode
595 is used to set the BIOS and power saving options on Toshiba portables.
597 For information on utilities to make use of this driver see the
598 Toshiba Linux utilities web site at:
599 <http://www.buzzard.org.uk/toshiba/>.
601 Say Y if you intend to run this kernel on a Toshiba portable.
605 tristate "Dell laptop support"
608 This adds a driver to safely access the System Management Mode
609 of the CPU on the Dell Inspiron 8000. The System Management Mode
610 is used to read cpu temperature and cooling fan status and to
611 control the fans on the I8K portables.
613 This driver has been tested only on the Inspiron 8000 but it may
614 also work with other Dell laptops. You can force loading on other
615 models by passing the parameter `force=1' to the module. Use at
618 For information on utilities to make use of this driver see the
619 I8K Linux utilities web site at:
620 <http://people.debian.org/~dz/i8k/>
622 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
625 config X86_REBOOTFIXUPS
626 bool "Enable X86 board specific fixups for reboot"
627 depends on X86_32 && X86
630 This enables chipset and/or board specific fixups to be done
631 in order to get reboot to work correctly. This is only needed on
632 some combinations of hardware and BIOS. The symptom, for which
633 this config is intended, is when reboot ends with a stalled/hung
636 Currently, the only fixup is for the Geode machines using
637 CS5530A and CS5536 chipsets.
639 Say Y if you want to enable the fixup. Currently, it's safe to
640 enable this option even if you don't need it.
644 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
647 If you say Y here, you will be able to update the microcode on
648 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
649 Pentium III, Pentium 4, Xeon etc. You will obviously need the
650 actual microcode binary data itself which is not shipped with the
653 For latest news and information on obtaining all the required
654 ingredients for this driver, check:
655 <http://www.urbanmyth.org/microcode/>.
657 To compile this driver as a module, choose M here: the
658 module will be called microcode.
660 config MICROCODE_OLD_INTERFACE
666 tristate "/dev/cpu/*/msr - Model-specific register support"
668 This device gives privileged processes access to the x86
669 Model-Specific Registers (MSRs). It is a character device with
670 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
671 MSR accesses are directed to a specific CPU on multi-processor
675 tristate "/dev/cpu/*/cpuid - CPU information support"
677 This device gives processes access to the x86 CPUID instruction to
678 be executed on a specific processor. It is a character device
679 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
683 prompt "High Memory Support"
684 default HIGHMEM4G if !X86_NUMAQ
685 default HIGHMEM64G if X86_NUMAQ
690 depends on !X86_NUMAQ
692 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
693 However, the address space of 32-bit x86 processors is only 4
694 Gigabytes large. That means that, if you have a large amount of
695 physical memory, not all of it can be "permanently mapped" by the
696 kernel. The physical memory that's not permanently mapped is called
699 If you are compiling a kernel which will never run on a machine with
700 more than 1 Gigabyte total physical RAM, answer "off" here (default
701 choice and suitable for most users). This will result in a "3GB/1GB"
702 split: 3GB are mapped so that each process sees a 3GB virtual memory
703 space and the remaining part of the 4GB virtual memory space is used
704 by the kernel to permanently map as much physical memory as
707 If the machine has between 1 and 4 Gigabytes physical RAM, then
710 If more than 4 Gigabytes is used then answer "64GB" here. This
711 selection turns Intel PAE (Physical Address Extension) mode on.
712 PAE implements 3-level paging on IA32 processors. PAE is fully
713 supported by Linux, PAE mode is implemented on all recent Intel
714 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
715 then the kernel will not boot on CPUs that don't support PAE!
717 The actual amount of total physical memory will either be
718 auto detected or can be forced by using a kernel command line option
719 such as "mem=256M". (Try "man bootparam" or see the documentation of
720 your boot loader (lilo or loadlin) about how to pass options to the
721 kernel at boot time.)
723 If unsure, say "off".
727 depends on !X86_NUMAQ
729 Select this if you have a 32-bit processor and between 1 and 4
730 gigabytes of physical RAM.
734 depends on !M386 && !M486
737 Select this if you have a 32-bit processor and more than 4
738 gigabytes of physical RAM.
743 depends on EXPERIMENTAL
744 prompt "Memory split" if EMBEDDED
748 Select the desired split between kernel and user memory.
750 If the address range available to the kernel is less than the
751 physical memory installed, the remaining memory will be available
752 as "high memory". Accessing high memory is a little more costly
753 than low memory, as it needs to be mapped into the kernel first.
754 Note that increasing the kernel address space limits the range
755 available to user programs, making the address space there
756 tighter. Selecting anything other than the default 3G/1G split
757 will also likely make your kernel incompatible with binary-only
760 If you are not absolutely sure what you are doing, leave this
764 bool "3G/1G user/kernel split"
765 config VMSPLIT_3G_OPT
767 bool "3G/1G user/kernel split (for full 1G low memory)"
769 bool "2G/2G user/kernel split"
770 config VMSPLIT_2G_OPT
772 bool "2G/2G user/kernel split (for full 2G low memory)"
774 bool "1G/3G user/kernel split"
779 default 0xB0000000 if VMSPLIT_3G_OPT
780 default 0x80000000 if VMSPLIT_2G
781 default 0x78000000 if VMSPLIT_2G_OPT
782 default 0x40000000 if VMSPLIT_1G
788 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
792 bool "PAE (Physical Address Extension) Support"
794 depends on X86_32 && !HIGHMEM4G
795 select RESOURCES_64BIT
797 PAE is required for NX support, and furthermore enables
798 larger swapspace support for non-overcommit purposes. It
799 has the cost of more pagetable lookup overhead, and also
800 consumes more pagetable space per process.
802 # Common NUMA Features
804 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
806 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL)
808 default y if (X86_NUMAQ || X86_SUMMIT)
810 Enable NUMA (Non Uniform Memory Access) support.
811 The kernel will try to allocate memory used by a CPU on the
812 local memory controller of the CPU and add some more
813 NUMA awareness to the kernel.
815 For i386 this is currently highly experimental and should be only
816 used for kernel development. It might also cause boot failures.
817 For x86_64 this is recommended on all multiprocessor Opteron systems.
818 If the system is EM64T, you should say N unless your system is
821 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
822 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
825 bool "Old style AMD Opteron NUMA detection"
826 depends on X86_64 && NUMA && PCI
829 Enable K8 NUMA node topology detection. You should say Y here if
830 you have a multi processor AMD K8 system. This uses an old
831 method to read the NUMA configuration directly from the builtin
832 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
833 instead, which also takes priority if both are compiled in.
835 config X86_64_ACPI_NUMA
836 bool "ACPI NUMA detection"
837 depends on X86_64 && NUMA && ACPI && PCI
841 Enable ACPI SRAT based node topology detection.
844 bool "NUMA emulation"
845 depends on X86_64 && NUMA
847 Enable NUMA emulation. A flat machine will be split
848 into virtual nodes when booted with "numa=fake=N", where N is the
849 number of nodes. This is only useful for debugging.
853 default "6" if X86_64
854 default "4" if X86_NUMAQ
856 depends on NEED_MULTIPLE_NODES
858 config HAVE_ARCH_BOOTMEM_NODE
860 depends on X86_32 && NUMA
863 config ARCH_HAVE_MEMORY_PRESENT
865 depends on X86_32 && DISCONTIGMEM
868 config NEED_NODE_MEMMAP_SIZE
870 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
873 config HAVE_ARCH_ALLOC_REMAP
875 depends on X86_32 && NUMA
878 config ARCH_FLATMEM_ENABLE
880 depends on (X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC) || (X86_64 && !NUMA)
882 config ARCH_DISCONTIGMEM_ENABLE
886 config ARCH_DISCONTIGMEM_DEFAULT
890 config ARCH_SPARSEMEM_ENABLE
892 depends on NUMA || (EXPERIMENTAL && (X86_PC || X86_64))
893 select SPARSEMEM_STATIC if X86_32
894 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
896 config ARCH_SELECT_MEMORY_MODEL
898 depends on X86_32 && ARCH_SPARSEMEM_ENABLE
900 config ARCH_MEMORY_PROBE
902 depends on MEMORY_HOTPLUG
907 bool "Allocate 3rd-level pagetables from highmem"
908 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
910 The VM uses one page table entry for each page of physical memory.
911 For systems with a lot of RAM, this can be wasteful of precious
912 low memory. Setting this option will put user-space page table
913 entries in high memory.
915 config MATH_EMULATION
917 prompt "Math emulation" if X86_32
919 Linux can emulate a math coprocessor (used for floating point
920 operations) if you don't have one. 486DX and Pentium processors have
921 a math coprocessor built in, 486SX and 386 do not, unless you added
922 a 487DX or 387, respectively. (The messages during boot time can
923 give you some hints here ["man dmesg"].) Everyone needs either a
924 coprocessor or this emulation.
926 If you don't have a math coprocessor, you need to say Y here; if you
927 say Y here even though you have a coprocessor, the coprocessor will
928 be used nevertheless. (This behavior can be changed with the kernel
929 command line option "no387", which comes handy if your coprocessor
930 is broken. Try "man bootparam" or see the documentation of your boot
931 loader (lilo or loadlin) about how to pass options to the kernel at
932 boot time.) This means that it is a good idea to say Y here if you
933 intend to use this kernel on different machines.
935 More information about the internals of the Linux math coprocessor
936 emulation can be found in <file:arch/x86/math-emu/README>.
938 If you are not sure, say Y; apart from resulting in a 66 KB bigger
939 kernel, it won't hurt.
942 bool "MTRR (Memory Type Range Register) support"
944 On Intel P6 family processors (Pentium Pro, Pentium II and later)
945 the Memory Type Range Registers (MTRRs) may be used to control
946 processor access to memory ranges. This is most useful if you have
947 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
948 allows bus write transfers to be combined into a larger transfer
949 before bursting over the PCI/AGP bus. This can increase performance
950 of image write operations 2.5 times or more. Saying Y here creates a
951 /proc/mtrr file which may be used to manipulate your processor's
952 MTRRs. Typically the X server should use this.
954 This code has a reasonably generic interface so that similar
955 control registers on other processors can be easily supported
958 The Cyrix 6x86, 6x86MX and M II processors have Address Range
959 Registers (ARRs) which provide a similar functionality to MTRRs. For
960 these, the ARRs are used to emulate the MTRRs.
961 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
962 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
963 write-combining. All of these processors are supported by this code
964 and it makes sense to say Y here if you have one of them.
966 Saying Y here also fixes a problem with buggy SMP BIOSes which only
967 set the MTRRs for the boot CPU and not for the secondary CPUs. This
968 can lead to all sorts of problems, so it's good to say Y here.
970 You can safely say Y even if your machine doesn't have MTRRs, you'll
971 just add about 9 KB to your kernel.
973 See <file:Documentation/mtrr.txt> for more information.
976 bool "Boot from EFI support"
977 depends on X86_32 && ACPI
980 This enables the kernel to boot on EFI platforms using
981 system configuration information passed to it from the firmware.
982 This also enables the kernel to use any EFI runtime services that are
983 available (such as the EFI variable services).
985 This option is only useful on systems that have EFI firmware
986 and will result in a kernel image that is ~8k larger. In addition,
987 you must use the latest ELILO loader available at
988 <http://elilo.sourceforge.net> in order to take advantage of
989 kernel initialization using EFI information (neither GRUB nor LILO know
990 anything about EFI). However, even with this option, the resultant
991 kernel should continue to boot on existing non-EFI platforms.
994 bool "Enable kernel irq balancing"
995 depends on X86_32 && SMP && X86_IO_APIC
998 The default yes will allow the kernel to do irq load balancing.
999 Saying no will keep the kernel from doing irq load balancing.
1001 # turning this on wastes a bunch of space.
1002 # Summit needs it only when NUMA is on
1005 depends on X86_32 && (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
1009 bool "Enable seccomp to safely compute untrusted bytecode"
1013 This kernel feature is useful for number crunching applications
1014 that may need to compute untrusted bytecode during their
1015 execution. By using pipes or other transports made available to
1016 the process as file descriptors supporting the read/write
1017 syscalls, it's possible to isolate those applications in
1018 their own address space using seccomp. Once seccomp is
1019 enabled via /proc/<pid>/seccomp, it cannot be disabled
1020 and the task is only allowed to execute a few safe syscalls
1021 defined by each seccomp mode.
1023 If unsure, say Y. Only embedded should say N here.
1025 config CC_STACKPROTECTOR
1026 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1027 depends on X86_64 && EXPERIMENTAL
1029 This option turns on the -fstack-protector GCC feature. This
1030 feature puts, at the beginning of critical functions, a canary
1031 value on the stack just before the return address, and validates
1032 the value just before actually returning. Stack based buffer
1033 overflows (that need to overwrite this return address) now also
1034 overwrite the canary, which gets detected and the attack is then
1035 neutralized via a kernel panic.
1037 This feature requires gcc version 4.2 or above, or a distribution
1038 gcc with the feature backported. Older versions are automatically
1039 detected and for those versions, this configuration option is ignored.
1041 config CC_STACKPROTECTOR_ALL
1042 bool "Use stack-protector for all functions"
1043 depends on CC_STACKPROTECTOR
1045 Normally, GCC only inserts the canary value protection for
1046 functions that use large-ish on-stack buffers. By enabling
1047 this option, GCC will be asked to do this for ALL functions.
1049 source kernel/Kconfig.hz
1052 bool "kexec system call"
1054 kexec is a system call that implements the ability to shutdown your
1055 current kernel, and to start another kernel. It is like a reboot
1056 but it is independent of the system firmware. And like a reboot
1057 you can start any kernel with it, not just Linux.
1059 The name comes from the similarity to the exec system call.
1061 It is an ongoing process to be certain the hardware in a machine
1062 is properly shutdown, so do not be surprised if this code does not
1063 initially work for you. It may help to enable device hotplugging
1064 support. As of this writing the exact hardware interface is
1065 strongly in flux, so no good recommendation can be made.
1068 bool "kernel crash dumps (EXPERIMENTAL)"
1069 depends on EXPERIMENTAL
1070 depends on X86_64 || (X86_32 && HIGHMEM)
1072 Generate crash dump after being started by kexec.
1073 This should be normally only set in special crash dump kernels
1074 which are loaded in the main kernel with kexec-tools into
1075 a specially reserved region and then later executed after
1076 a crash by kdump/kexec. The crash dump kernel must be compiled
1077 to a memory address not used by the main kernel or BIOS using
1078 PHYSICAL_START, or it must be built as a relocatable image
1079 (CONFIG_RELOCATABLE=y).
1080 For more details see Documentation/kdump/kdump.txt
1082 config PHYSICAL_START
1083 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1084 default "0x1000000" if X86_NUMAQ
1085 default "0x200000" if X86_64
1088 This gives the physical address where the kernel is loaded.
1090 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1091 bzImage will decompress itself to above physical address and
1092 run from there. Otherwise, bzImage will run from the address where
1093 it has been loaded by the boot loader and will ignore above physical
1096 In normal kdump cases one does not have to set/change this option
1097 as now bzImage can be compiled as a completely relocatable image
1098 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1099 address. This option is mainly useful for the folks who don't want
1100 to use a bzImage for capturing the crash dump and want to use a
1101 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1102 to be specifically compiled to run from a specific memory area
1103 (normally a reserved region) and this option comes handy.
1105 So if you are using bzImage for capturing the crash dump, leave
1106 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1107 Otherwise if you plan to use vmlinux for capturing the crash dump
1108 change this value to start of the reserved region (Typically 16MB
1109 0x1000000). In other words, it can be set based on the "X" value as
1110 specified in the "crashkernel=YM@XM" command line boot parameter
1111 passed to the panic-ed kernel. Typically this parameter is set as
1112 crashkernel=64M@16M. Please take a look at
1113 Documentation/kdump/kdump.txt for more details about crash dumps.
1115 Usage of bzImage for capturing the crash dump is recommended as
1116 one does not have to build two kernels. Same kernel can be used
1117 as production kernel and capture kernel. Above option should have
1118 gone away after relocatable bzImage support is introduced. But it
1119 is present because there are users out there who continue to use
1120 vmlinux for dump capture. This option should go away down the
1123 Don't change this unless you know what you are doing.
1126 bool "Build a relocatable kernel (EXPERIMENTAL)"
1127 depends on EXPERIMENTAL
1129 This builds a kernel image that retains relocation information
1130 so it can be loaded someplace besides the default 1MB.
1131 The relocations tend to make the kernel binary about 10% larger,
1132 but are discarded at runtime.
1134 One use is for the kexec on panic case where the recovery kernel
1135 must live at a different physical address than the primary
1138 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1139 it has been loaded at and the compile time physical address
1140 (CONFIG_PHYSICAL_START) is ignored.
1142 config PHYSICAL_ALIGN
1144 prompt "Alignment value to which kernel should be aligned" if X86_32
1145 default "0x100000" if X86_32
1146 default "0x200000" if X86_64
1147 range 0x2000 0x400000
1149 This value puts the alignment restrictions on physical address
1150 where kernel is loaded and run from. Kernel is compiled for an
1151 address which meets above alignment restriction.
1153 If bootloader loads the kernel at a non-aligned address and
1154 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1155 address aligned to above value and run from there.
1157 If bootloader loads the kernel at a non-aligned address and
1158 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1159 load address and decompress itself to the address it has been
1160 compiled for and run from there. The address for which kernel is
1161 compiled already meets above alignment restrictions. Hence the
1162 end result is that kernel runs from a physical address meeting
1163 above alignment restrictions.
1165 Don't change this unless you know what you are doing.
1168 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1169 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1171 Say Y here to experiment with turning CPUs off and on, and to
1172 enable suspend on SMP systems. CPUs can be controlled through
1173 /sys/devices/system/cpu.
1174 Say N if you want to disable CPU hotplug and don't need to
1178 bool "Compat VDSO support"
1182 Map the VDSO to the predictable old-style address too.
1184 Say N here if you are running a sufficiently recent glibc
1185 version (2.3.3 or later), to remove the high-mapped
1186 VDSO mapping and to exclusively use the randomized VDSO.
1192 config ARCH_ENABLE_MEMORY_HOTPLUG
1194 depends on X86_64 || (X86_32 && HIGHMEM)
1196 config MEMORY_HOTPLUG_RESERVE
1198 depends on (MEMORY_HOTPLUG && DISCONTIGMEM)
1200 config HAVE_ARCH_EARLY_PFN_TO_NID
1204 config OUT_OF_LINE_PFN_TO_PAGE
1206 depends on DISCONTIGMEM
1208 menu "Power management options"
1209 depends on !X86_VOYAGER
1211 config ARCH_HIBERNATION_HEADER
1213 depends on X86_64 && HIBERNATION
1216 source "kernel/power/Kconfig"
1218 source "drivers/acpi/Kconfig"
1221 tristate "APM (Advanced Power Management) BIOS support"
1222 depends on X86_32 && PM_SLEEP && !X86_VISWS
1224 APM is a BIOS specification for saving power using several different
1225 techniques. This is mostly useful for battery powered laptops with
1226 APM compliant BIOSes. If you say Y here, the system time will be
1227 reset after a RESUME operation, the /proc/apm device will provide
1228 battery status information, and user-space programs will receive
1229 notification of APM "events" (e.g. battery status change).
1231 If you select "Y" here, you can disable actual use of the APM
1232 BIOS by passing the "apm=off" option to the kernel at boot time.
1234 Note that the APM support is almost completely disabled for
1235 machines with more than one CPU.
1237 In order to use APM, you will need supporting software. For location
1238 and more information, read <file:Documentation/pm.txt> and the
1239 Battery Powered Linux mini-HOWTO, available from
1240 <http://www.tldp.org/docs.html#howto>.
1242 This driver does not spin down disk drives (see the hdparm(8)
1243 manpage ("man 8 hdparm") for that), and it doesn't turn off
1244 VESA-compliant "green" monitors.
1246 This driver does not support the TI 4000M TravelMate and the ACER
1247 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1248 desktop machines also don't have compliant BIOSes, and this driver
1249 may cause those machines to panic during the boot phase.
1251 Generally, if you don't have a battery in your machine, there isn't
1252 much point in using this driver and you should say N. If you get
1253 random kernel OOPSes or reboots that don't seem to be related to
1254 anything, try disabling/enabling this option (or disabling/enabling
1257 Some other things you should try when experiencing seemingly random,
1260 1) make sure that you have enough swap space and that it is
1262 2) pass the "no-hlt" option to the kernel
1263 3) switch on floating point emulation in the kernel and pass
1264 the "no387" option to the kernel
1265 4) pass the "floppy=nodma" option to the kernel
1266 5) pass the "mem=4M" option to the kernel (thereby disabling
1267 all but the first 4 MB of RAM)
1268 6) make sure that the CPU is not over clocked.
1269 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1270 8) disable the cache from your BIOS settings
1271 9) install a fan for the video card or exchange video RAM
1272 10) install a better fan for the CPU
1273 11) exchange RAM chips
1274 12) exchange the motherboard.
1276 To compile this driver as a module, choose M here: the
1277 module will be called apm.
1281 config APM_IGNORE_USER_SUSPEND
1282 bool "Ignore USER SUSPEND"
1284 This option will ignore USER SUSPEND requests. On machines with a
1285 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1286 series notebooks, it is necessary to say Y because of a BIOS bug.
1288 config APM_DO_ENABLE
1289 bool "Enable PM at boot time"
1291 Enable APM features at boot time. From page 36 of the APM BIOS
1292 specification: "When disabled, the APM BIOS does not automatically
1293 power manage devices, enter the Standby State, enter the Suspend
1294 State, or take power saving steps in response to CPU Idle calls."
1295 This driver will make CPU Idle calls when Linux is idle (unless this
1296 feature is turned off -- see "Do CPU IDLE calls", below). This
1297 should always save battery power, but more complicated APM features
1298 will be dependent on your BIOS implementation. You may need to turn
1299 this option off if your computer hangs at boot time when using APM
1300 support, or if it beeps continuously instead of suspending. Turn
1301 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1302 T400CDT. This is off by default since most machines do fine without
1306 bool "Make CPU Idle calls when idle"
1308 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1309 On some machines, this can activate improved power savings, such as
1310 a slowed CPU clock rate, when the machine is idle. These idle calls
1311 are made after the idle loop has run for some length of time (e.g.,
1312 333 mS). On some machines, this will cause a hang at boot time or
1313 whenever the CPU becomes idle. (On machines with more than one CPU,
1314 this option does nothing.)
1316 config APM_DISPLAY_BLANK
1317 bool "Enable console blanking using APM"
1319 Enable console blanking using the APM. Some laptops can use this to
1320 turn off the LCD backlight when the screen blanker of the Linux
1321 virtual console blanks the screen. Note that this is only used by
1322 the virtual console screen blanker, and won't turn off the backlight
1323 when using the X Window system. This also doesn't have anything to
1324 do with your VESA-compliant power-saving monitor. Further, this
1325 option doesn't work for all laptops -- it might not turn off your
1326 backlight at all, or it might print a lot of errors to the console,
1327 especially if you are using gpm.
1329 config APM_ALLOW_INTS
1330 bool "Allow interrupts during APM BIOS calls"
1332 Normally we disable external interrupts while we are making calls to
1333 the APM BIOS as a measure to lessen the effects of a badly behaving
1334 BIOS implementation. The BIOS should reenable interrupts if it
1335 needs to. Unfortunately, some BIOSes do not -- especially those in
1336 many of the newer IBM Thinkpads. If you experience hangs when you
1337 suspend, try setting this to Y. Otherwise, say N.
1339 config APM_REAL_MODE_POWER_OFF
1340 bool "Use real mode APM BIOS call to power off"
1342 Use real mode APM BIOS calls to switch off the computer. This is
1343 a work-around for a number of buggy BIOSes. Switch this option on if
1344 your computer crashes instead of powering off properly.
1348 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1350 source "drivers/cpuidle/Kconfig"
1355 menu "Bus options (PCI etc.)"
1358 bool "PCI support" if !X86_VISWS
1359 depends on !X86_VOYAGER
1360 default y if X86_VISWS
1361 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1363 Find out whether you have a PCI motherboard. PCI is the name of a
1364 bus system, i.e. the way the CPU talks to the other stuff inside
1365 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1366 VESA. If you have PCI, say Y, otherwise N.
1368 The PCI-HOWTO, available from
1369 <http://www.tldp.org/docs.html#howto>, contains valuable
1370 information about which PCI hardware does work under Linux and which
1374 prompt "PCI access mode"
1375 depends on X86_32 && PCI && !X86_VISWS
1378 On PCI systems, the BIOS can be used to detect the PCI devices and
1379 determine their configuration. However, some old PCI motherboards
1380 have BIOS bugs and may crash if this is done. Also, some embedded
1381 PCI-based systems don't have any BIOS at all. Linux can also try to
1382 detect the PCI hardware directly without using the BIOS.
1384 With this option, you can specify how Linux should detect the
1385 PCI devices. If you choose "BIOS", the BIOS will be used,
1386 if you choose "Direct", the BIOS won't be used, and if you
1387 choose "MMConfig", then PCI Express MMCONFIG will be used.
1388 If you choose "Any", the kernel will try MMCONFIG, then the
1389 direct access method and falls back to the BIOS if that doesn't
1390 work. If unsure, go with the default, which is "Any".
1395 config PCI_GOMMCONFIG
1408 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1411 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1414 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1419 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1428 bool "Support mmconfig PCI config space access"
1429 depends on X86_64 && PCI && ACPI
1432 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1433 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1435 DMA remapping (DMAR) devices support enables independent address
1436 translations for Direct Memory Access (DMA) from devices.
1437 These DMA remapping devices are reported via ACPI tables
1438 and include PCI device scope covered by these DMA
1442 bool "Support for Graphics workaround"
1446 Current Graphics drivers tend to use physical address
1447 for DMA and avoid using DMA APIs. Setting this config
1448 option permits the IOMMU driver to set a unity map for
1449 all the OS-visible memory. Hence the driver can continue
1450 to use physical addresses for DMA.
1452 config DMAR_FLOPPY_WA
1457 Floppy disk drivers are know to bypass DMA API calls
1458 thereby failing to work when IOMMU is enabled. This
1459 workaround will setup a 1:1 mapping for the first
1460 16M to make floppy (an ISA device) work.
1462 source "drivers/pci/pcie/Kconfig"
1464 source "drivers/pci/Kconfig"
1466 # x86_64 have no ISA slots, but do have ISA-style DMA.
1475 depends on !(X86_VOYAGER || X86_VISWS)
1477 Find out whether you have ISA slots on your motherboard. ISA is the
1478 name of a bus system, i.e. the way the CPU talks to the other stuff
1479 inside your box. Other bus systems are PCI, EISA, MicroChannel
1480 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1481 newer boards don't support it. If you have ISA, say Y, otherwise N.
1487 The Extended Industry Standard Architecture (EISA) bus was
1488 developed as an open alternative to the IBM MicroChannel bus.
1490 The EISA bus provided some of the features of the IBM MicroChannel
1491 bus while maintaining backward compatibility with cards made for
1492 the older ISA bus. The EISA bus saw limited use between 1988 and
1493 1995 when it was made obsolete by the PCI bus.
1495 Say Y here if you are building a kernel for an EISA-based machine.
1499 source "drivers/eisa/Kconfig"
1502 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1503 default y if X86_VOYAGER
1505 MicroChannel Architecture is found in some IBM PS/2 machines and
1506 laptops. It is a bus system similar to PCI or ISA. See
1507 <file:Documentation/mca.txt> (and especially the web page given
1508 there) before attempting to build an MCA bus kernel.
1510 source "drivers/mca/Kconfig"
1513 tristate "NatSemi SCx200 support"
1514 depends on !X86_VOYAGER
1516 This provides basic support for National Semiconductor's
1517 (now AMD's) Geode processors. The driver probes for the
1518 PCI-IDs of several on-chip devices, so its a good dependency
1519 for other scx200_* drivers.
1521 If compiled as a module, the driver is named scx200.
1523 config SCx200HR_TIMER
1524 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1525 depends on SCx200 && GENERIC_TIME
1528 This driver provides a clocksource built upon the on-chip
1529 27MHz high-resolution timer. Its also a workaround for
1530 NSC Geode SC-1100's buggy TSC, which loses time when the
1531 processor goes idle (as is done by the scheduler). The
1532 other workaround is idle=poll boot option.
1534 config GEODE_MFGPT_TIMER
1535 bool "Geode Multi-Function General Purpose Timer (MFGPT) events"
1536 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1539 This driver provides a clock event source based on the MFGPT
1540 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1541 MFGPTs have a better resolution and max interval than the
1542 generic PIT, and are suitable for use as high-res timers.
1548 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1550 source "drivers/pcmcia/Kconfig"
1552 source "drivers/pci/hotplug/Kconfig"
1557 menu "Executable file formats / Emulations"
1559 source "fs/Kconfig.binfmt"
1561 config IA32_EMULATION
1562 bool "IA32 Emulation"
1565 Include code to run 32-bit programs under a 64-bit kernel. You should
1566 likely turn this on, unless you're 100% sure that you don't have any
1567 32-bit programs left.
1570 tristate "IA32 a.out support"
1571 depends on IA32_EMULATION
1573 Support old a.out binaries in the 32bit emulation.
1577 depends on IA32_EMULATION
1580 config COMPAT_FOR_U64_ALIGNMENT
1584 config SYSVIPC_COMPAT
1586 depends on X86_64 && COMPAT && SYSVIPC
1592 source "net/Kconfig"
1594 source "drivers/Kconfig"
1596 source "drivers/firmware/Kconfig"
1600 source "kernel/Kconfig.instrumentation"
1602 source "arch/x86/Kconfig.debug"
1604 source "security/Kconfig"
1606 source "crypto/Kconfig"
1608 source "lib/Kconfig"
projects / linux-2.6-omap-h63xx.git / blob