2 mainmenu "Linux Kernel Configuration for x86"
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
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
21 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_KRETPROBES
26 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
27 select HAVE_ARCH_KGDB if !X86_VOYAGER
33 default "arch/x86/configs/i386_defconfig"
39 default "arch/x86/configs/x86_64_defconfig"
42 config GENERIC_LOCKBREAK
48 config GENERIC_CMOS_UPDATE
51 config CLOCKSOURCE_WATCHDOG
54 config GENERIC_CLOCKEVENTS
57 config GENERIC_CLOCKEVENTS_BROADCAST
59 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
61 config LOCKDEP_SUPPORT
64 config STACKTRACE_SUPPORT
67 config HAVE_LATENCYTOP_SUPPORT
70 config FAST_CMPXCHG_LOCAL
83 config GENERIC_ISA_DMA
93 config GENERIC_HWEIGHT
99 config ARCH_MAY_HAVE_PC_FDC
102 config RWSEM_GENERIC_SPINLOCK
105 config RWSEM_XCHGADD_ALGORITHM
108 config ARCH_HAS_ILOG2_U32
111 config ARCH_HAS_ILOG2_U64
114 config ARCH_HAS_CPU_IDLE_WAIT
117 config GENERIC_CALIBRATE_DELAY
120 config GENERIC_TIME_VSYSCALL
124 config ARCH_HAS_CPU_RELAX
127 config ARCH_HAS_CACHE_LINE_SIZE
130 config HAVE_SETUP_PER_CPU_AREA
131 def_bool X86_64 || (X86_SMP && !X86_VOYAGER)
133 config HAVE_CPUMASK_OF_CPU_MAP
136 config ARCH_HIBERNATION_POSSIBLE
138 depends on !SMP || !X86_VOYAGER
140 config ARCH_SUSPEND_POSSIBLE
142 depends on !X86_VOYAGER
148 config ARCH_POPULATES_NODE_MAP
155 config ARCH_SUPPORTS_AOUT
158 config ARCH_SUPPORTS_OPTIMIZED_INLINING
161 # Use the generic interrupt handling code in kernel/irq/:
162 config GENERIC_HARDIRQS
166 config GENERIC_IRQ_PROBE
170 config GENERIC_PENDING_IRQ
172 depends on GENERIC_HARDIRQS && SMP
177 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
182 depends on X86_32 && SMP
186 depends on X86_64 && SMP
191 depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || X86_64
194 config X86_BIOS_REBOOT
196 depends on !X86_VISWS && !X86_VOYAGER
199 config X86_TRAMPOLINE
201 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
206 source "init/Kconfig"
208 menu "Processor type and features"
210 source "kernel/time/Kconfig"
213 bool "Symmetric multi-processing support"
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.
241 prompt "Subarchitecture Type"
247 Choose this option if your computer is a standard PC or compatible.
253 Select this for an AMD Elan processor.
255 Do not use this option for K6/Athlon/Opteron processors!
257 If unsure, choose "PC-compatible" instead.
261 depends on X86_32 && (SMP || BROKEN)
263 Voyager is an MCA-based 32-way capable SMP architecture proprietary
264 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
268 If you do not specifically know you have a Voyager based machine,
269 say N here, otherwise the kernel you build will not be bootable.
272 bool "SGI 320/540 (Visual Workstation)"
275 The SGI Visual Workstation series is an IA32-based workstation
276 based on SGI systems chips with some legacy PC hardware attached.
278 Say Y here to create a kernel to run on the SGI 320 or 540.
280 A kernel compiled for the Visual Workstation will not run on PCs
281 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
283 config X86_GENERICARCH
284 bool "Generic architecture"
287 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
288 subarchitectures. It is intended for a generic binary kernel.
289 if you select them all, kernel will probe it one by one. and will
295 bool "NUMAQ (IBM/Sequent)"
296 depends on SMP && X86_32
299 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
300 NUMA multiquad box. This changes the way that processors are
301 bootstrapped, and uses Clustered Logical APIC addressing mode instead
302 of Flat Logical. You will need a new lynxer.elf file to flash your
303 firmware with - send email to <Martin.Bligh@us.ibm.com>.
306 bool "Summit/EXA (IBM x440)"
307 depends on X86_32 && SMP
309 This option is needed for IBM systems that use the Summit/EXA chipset.
310 In particular, it is needed for the x440.
313 bool "Support for Unisys ES7000 IA32 series"
314 depends on X86_32 && SMP
316 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
317 supposed to run on an IA32-based Unisys ES7000 system.
320 bool "Support for big SMP systems with more than 8 CPUs"
321 depends on X86_32 && SMP
323 This option is needed for the systems that have more than 8 CPUs
324 and if the system is not of any sub-arch type above.
329 bool "RDC R-321x SoC"
332 select X86_REBOOTFIXUPS
338 This option is needed for RDC R-321x system-on-chip, also known
340 If you don't have one of these chips, you should say N here.
343 bool "Support for ScaleMP vSMP"
347 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
348 supposed to run on these EM64T-based machines. Only choose this option
349 if you have one of these machines.
353 config SCHED_NO_NO_OMIT_FRAME_POINTER
355 prompt "Single-depth WCHAN output"
358 Calculate simpler /proc/<PID>/wchan values. If this option
359 is disabled then wchan values will recurse back to the
360 caller function. This provides more accurate wchan values,
361 at the expense of slightly more scheduling overhead.
363 If in doubt, say "Y".
365 menuconfig PARAVIRT_GUEST
366 bool "Paravirtualized guest support"
368 Say Y here to get to see options related to running Linux under
369 various hypervisors. This option alone does not add any kernel code.
371 If you say N, all options in this submenu will be skipped and disabled.
375 source "arch/x86/xen/Kconfig"
378 bool "VMI Guest support"
381 depends on !(X86_VISWS || X86_VOYAGER)
383 VMI provides a paravirtualized interface to the VMware ESX server
384 (it could be used by other hypervisors in theory too, but is not
385 at the moment), by linking the kernel to a GPL-ed ROM module
386 provided by the hypervisor.
389 bool "KVM paravirtualized clock"
391 depends on !(X86_VISWS || X86_VOYAGER)
393 Turning on this option will allow you to run a paravirtualized clock
394 when running over the KVM hypervisor. Instead of relying on a PIT
395 (or probably other) emulation by the underlying device model, the host
396 provides the guest with timing infrastructure such as time of day, and
400 bool "KVM Guest support"
402 depends on !(X86_VISWS || X86_VOYAGER)
404 This option enables various optimizations for running under the KVM
407 source "arch/x86/lguest/Kconfig"
410 bool "Enable paravirtualization code"
411 depends on !(X86_VISWS || X86_VOYAGER)
413 This changes the kernel so it can modify itself when it is run
414 under a hypervisor, potentially improving performance significantly
415 over full virtualization. However, when run without a hypervisor
416 the kernel is theoretically slower and slightly larger.
420 config MEMTEST_BOOTPARAM
421 bool "Memtest boot parameter"
425 This option adds a kernel parameter 'memtest', which allows memtest
426 to be disabled at boot. If this option is selected, memtest
427 functionality can be disabled with memtest=0 on the kernel
428 command line. The purpose of this option is to allow a single
429 kernel image to be distributed with memtest built in, but not
432 If you are unsure how to answer this question, answer Y.
434 config MEMTEST_BOOTPARAM_VALUE
435 int "Memtest boot parameter default value (0-4)"
436 depends on MEMTEST_BOOTPARAM
440 This option sets the default value for the kernel parameter
441 'memtest', which allows memtest to be disabled at boot. If this
442 option is set to 0 (zero), the memtest kernel parameter will
443 default to 0, disabling memtest at bootup. If this option is
444 set to 4, the memtest kernel parameter will default to 4,
445 enabling memtest at bootup, and use that as pattern number.
447 If you are unsure how to answer this question, answer 0.
451 depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
454 config HAVE_ARCH_PARSE_SRAT
458 config X86_SUMMIT_NUMA
460 depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
462 config X86_CYCLONE_TIMER
464 depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
466 config ES7000_CLUSTERED_APIC
468 depends on SMP && X86_ES7000 && MPENTIUMIII
470 source "arch/x86/Kconfig.cpu"
474 prompt "HPET Timer Support" if X86_32
476 Use the IA-PC HPET (High Precision Event Timer) to manage
477 time in preference to the PIT and RTC, if a HPET is
479 HPET is the next generation timer replacing legacy 8254s.
480 The HPET provides a stable time base on SMP
481 systems, unlike the TSC, but it is more expensive to access,
482 as it is off-chip. You can find the HPET spec at
483 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
485 You can safely choose Y here. However, HPET will only be
486 activated if the platform and the BIOS support this feature.
487 Otherwise the 8254 will be used for timing services.
489 Choose N to continue using the legacy 8254 timer.
491 config HPET_EMULATE_RTC
493 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
495 # Mark as embedded because too many people got it wrong.
496 # The code disables itself when not needed.
499 bool "Enable DMI scanning" if EMBEDDED
501 Enabled scanning of DMI to identify machine quirks. Say Y
502 here unless you have verified that your setup is not
503 affected by entries in the DMI blacklist. Required by PNP
507 bool "GART IOMMU support" if EMBEDDED
511 depends on X86_64 && PCI
513 Support for full DMA access of devices with 32bit memory access only
514 on systems with more than 3GB. This is usually needed for USB,
515 sound, many IDE/SATA chipsets and some other devices.
516 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
517 based hardware IOMMU and a software bounce buffer based IOMMU used
518 on Intel systems and as fallback.
519 The code is only active when needed (enough memory and limited
520 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
524 bool "IBM Calgary IOMMU support"
526 depends on X86_64 && PCI && EXPERIMENTAL
528 Support for hardware IOMMUs in IBM's xSeries x366 and x460
529 systems. Needed to run systems with more than 3GB of memory
530 properly with 32-bit PCI devices that do not support DAC
531 (Double Address Cycle). Calgary also supports bus level
532 isolation, where all DMAs pass through the IOMMU. This
533 prevents them from going anywhere except their intended
534 destination. This catches hard-to-find kernel bugs and
535 mis-behaving drivers and devices that do not use the DMA-API
536 properly to set up their DMA buffers. The IOMMU can be
537 turned off at boot time with the iommu=off parameter.
538 Normally the kernel will make the right choice by itself.
541 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
543 prompt "Should Calgary be enabled by default?"
544 depends on CALGARY_IOMMU
546 Should Calgary be enabled by default? if you choose 'y', Calgary
547 will be used (if it exists). If you choose 'n', Calgary will not be
548 used even if it exists. If you choose 'n' and would like to use
549 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
552 # need this always selected by IOMMU for the VIA workaround
556 Support for software bounce buffers used on x86-64 systems
557 which don't have a hardware IOMMU (e.g. the current generation
558 of Intel's x86-64 CPUs). Using this PCI devices which can only
559 access 32-bits of memory can be used on systems with more than
560 3 GB of memory. If unsure, say Y.
563 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB)
566 int "Maximum number of CPUs (2-255)"
569 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
572 This allows you to specify the maximum number of CPUs which this
573 kernel will support. The maximum supported value is 255 and the
574 minimum value which makes sense is 2.
576 This is purely to save memory - each supported CPU adds
577 approximately eight kilobytes to the kernel image.
580 bool "SMT (Hyperthreading) scheduler support"
583 SMT scheduler support improves the CPU scheduler's decision making
584 when dealing with Intel Pentium 4 chips with HyperThreading at a
585 cost of slightly increased overhead in some places. If unsure say
590 prompt "Multi-core scheduler support"
593 Multi-core scheduler support improves the CPU scheduler's decision
594 making when dealing with multi-core CPU chips at a cost of slightly
595 increased overhead in some places. If unsure say N here.
597 source "kernel/Kconfig.preempt"
600 bool "Local APIC support on uniprocessors"
601 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
603 A local APIC (Advanced Programmable Interrupt Controller) is an
604 integrated interrupt controller in the CPU. If you have a single-CPU
605 system which has a processor with a local APIC, you can say Y here to
606 enable and use it. If you say Y here even though your machine doesn't
607 have a local APIC, then the kernel will still run with no slowdown at
608 all. The local APIC supports CPU-generated self-interrupts (timer,
609 performance counters), and the NMI watchdog which detects hard
613 bool "IO-APIC support on uniprocessors"
614 depends on X86_UP_APIC
616 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
617 SMP-capable replacement for PC-style interrupt controllers. Most
618 SMP systems and many recent uniprocessor systems have one.
620 If you have a single-CPU system with an IO-APIC, you can say Y here
621 to use it. If you say Y here even though your machine doesn't have
622 an IO-APIC, then the kernel will still run with no slowdown at all.
624 config X86_LOCAL_APIC
626 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
630 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
632 config X86_VISWS_APIC
634 depends on X86_32 && X86_VISWS
637 bool "Machine Check Exception"
638 depends on !X86_VOYAGER
640 Machine Check Exception support allows the processor to notify the
641 kernel if it detects a problem (e.g. overheating, component failure).
642 The action the kernel takes depends on the severity of the problem,
643 ranging from a warning message on the console, to halting the machine.
644 Your processor must be a Pentium or newer to support this - check the
645 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
646 have a design flaw which leads to false MCE events - hence MCE is
647 disabled on all P5 processors, unless explicitly enabled with "mce"
648 as a boot argument. Similarly, if MCE is built in and creates a
649 problem on some new non-standard machine, you can boot with "nomce"
650 to disable it. MCE support simply ignores non-MCE processors like
651 the 386 and 486, so nearly everyone can say Y here.
655 prompt "Intel MCE features"
656 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
658 Additional support for intel specific MCE features such as
663 prompt "AMD MCE features"
664 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
666 Additional support for AMD specific MCE features such as
667 the DRAM Error Threshold.
669 config X86_MCE_NONFATAL
670 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
671 depends on X86_32 && X86_MCE
673 Enabling this feature starts a timer that triggers every 5 seconds which
674 will look at the machine check registers to see if anything happened.
675 Non-fatal problems automatically get corrected (but still logged).
676 Disable this if you don't want to see these messages.
677 Seeing the messages this option prints out may be indicative of dying
678 or out-of-spec (ie, overclocked) hardware.
679 This option only does something on certain CPUs.
680 (AMD Athlon/Duron and Intel Pentium 4)
682 config X86_MCE_P4THERMAL
683 bool "check for P4 thermal throttling interrupt."
684 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
686 Enabling this feature will cause a message to be printed when the P4
687 enters thermal throttling.
690 bool "Enable VM86 support" if EMBEDDED
694 This option is required by programs like DOSEMU to run 16-bit legacy
695 code on X86 processors. It also may be needed by software like
696 XFree86 to initialize some video cards via BIOS. Disabling this
697 option saves about 6k.
700 tristate "Toshiba Laptop support"
703 This adds a driver to safely access the System Management Mode of
704 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
705 not work on models with a Phoenix BIOS. The System Management Mode
706 is used to set the BIOS and power saving options on Toshiba portables.
708 For information on utilities to make use of this driver see the
709 Toshiba Linux utilities web site at:
710 <http://www.buzzard.org.uk/toshiba/>.
712 Say Y if you intend to run this kernel on a Toshiba portable.
716 tristate "Dell laptop support"
718 This adds a driver to safely access the System Management Mode
719 of the CPU on the Dell Inspiron 8000. The System Management Mode
720 is used to read cpu temperature and cooling fan status and to
721 control the fans on the I8K portables.
723 This driver has been tested only on the Inspiron 8000 but it may
724 also work with other Dell laptops. You can force loading on other
725 models by passing the parameter `force=1' to the module. Use at
728 For information on utilities to make use of this driver see the
729 I8K Linux utilities web site at:
730 <http://people.debian.org/~dz/i8k/>
732 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
735 config X86_REBOOTFIXUPS
737 prompt "Enable X86 board specific fixups for reboot"
738 depends on X86_32 && X86
740 This enables chipset and/or board specific fixups to be done
741 in order to get reboot to work correctly. This is only needed on
742 some combinations of hardware and BIOS. The symptom, for which
743 this config is intended, is when reboot ends with a stalled/hung
746 Currently, the only fixup is for the Geode machines using
747 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
749 Say Y if you want to enable the fixup. Currently, it's safe to
750 enable this option even if you don't need it.
754 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
757 If you say Y here, you will be able to update the microcode on
758 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
759 Pentium III, Pentium 4, Xeon etc. You will obviously need the
760 actual microcode binary data itself which is not shipped with the
763 For latest news and information on obtaining all the required
764 ingredients for this driver, check:
765 <http://www.urbanmyth.org/microcode/>.
767 To compile this driver as a module, choose M here: the
768 module will be called microcode.
770 config MICROCODE_OLD_INTERFACE
775 tristate "/dev/cpu/*/msr - Model-specific register support"
777 This device gives privileged processes access to the x86
778 Model-Specific Registers (MSRs). It is a character device with
779 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
780 MSR accesses are directed to a specific CPU on multi-processor
784 tristate "/dev/cpu/*/cpuid - CPU information support"
786 This device gives processes access to the x86 CPUID instruction to
787 be executed on a specific processor. It is a character device
788 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
792 prompt "High Memory Support"
793 default HIGHMEM4G if !X86_NUMAQ
794 default HIGHMEM64G if X86_NUMAQ
799 depends on !X86_NUMAQ
801 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
802 However, the address space of 32-bit x86 processors is only 4
803 Gigabytes large. That means that, if you have a large amount of
804 physical memory, not all of it can be "permanently mapped" by the
805 kernel. The physical memory that's not permanently mapped is called
808 If you are compiling a kernel which will never run on a machine with
809 more than 1 Gigabyte total physical RAM, answer "off" here (default
810 choice and suitable for most users). This will result in a "3GB/1GB"
811 split: 3GB are mapped so that each process sees a 3GB virtual memory
812 space and the remaining part of the 4GB virtual memory space is used
813 by the kernel to permanently map as much physical memory as
816 If the machine has between 1 and 4 Gigabytes physical RAM, then
819 If more than 4 Gigabytes is used then answer "64GB" here. This
820 selection turns Intel PAE (Physical Address Extension) mode on.
821 PAE implements 3-level paging on IA32 processors. PAE is fully
822 supported by Linux, PAE mode is implemented on all recent Intel
823 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
824 then the kernel will not boot on CPUs that don't support PAE!
826 The actual amount of total physical memory will either be
827 auto detected or can be forced by using a kernel command line option
828 such as "mem=256M". (Try "man bootparam" or see the documentation of
829 your boot loader (lilo or loadlin) about how to pass options to the
830 kernel at boot time.)
832 If unsure, say "off".
836 depends on !X86_NUMAQ
838 Select this if you have a 32-bit processor and between 1 and 4
839 gigabytes of physical RAM.
843 depends on !M386 && !M486
846 Select this if you have a 32-bit processor and more than 4
847 gigabytes of physical RAM.
852 depends on EXPERIMENTAL
853 prompt "Memory split" if EMBEDDED
857 Select the desired split between kernel and user memory.
859 If the address range available to the kernel is less than the
860 physical memory installed, the remaining memory will be available
861 as "high memory". Accessing high memory is a little more costly
862 than low memory, as it needs to be mapped into the kernel first.
863 Note that increasing the kernel address space limits the range
864 available to user programs, making the address space there
865 tighter. Selecting anything other than the default 3G/1G split
866 will also likely make your kernel incompatible with binary-only
869 If you are not absolutely sure what you are doing, leave this
873 bool "3G/1G user/kernel split"
874 config VMSPLIT_3G_OPT
876 bool "3G/1G user/kernel split (for full 1G low memory)"
878 bool "2G/2G user/kernel split"
879 config VMSPLIT_2G_OPT
881 bool "2G/2G user/kernel split (for full 2G low memory)"
883 bool "1G/3G user/kernel split"
888 default 0xB0000000 if VMSPLIT_3G_OPT
889 default 0x80000000 if VMSPLIT_2G
890 default 0x78000000 if VMSPLIT_2G_OPT
891 default 0x40000000 if VMSPLIT_1G
897 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
901 prompt "PAE (Physical Address Extension) Support"
902 depends on X86_32 && !HIGHMEM4G
903 select RESOURCES_64BIT
905 PAE is required for NX support, and furthermore enables
906 larger swapspace support for non-overcommit purposes. It
907 has the cost of more pagetable lookup overhead, and also
908 consumes more pagetable space per process.
910 # Common NUMA Features
912 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
914 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || X86_SUMMIT && ACPI) && EXPERIMENTAL)
916 default y if (X86_NUMAQ || X86_SUMMIT || X86_GENERICARCH)
918 Enable NUMA (Non Uniform Memory Access) support.
919 The kernel will try to allocate memory used by a CPU on the
920 local memory controller of the CPU and add some more
921 NUMA awareness to the kernel.
923 For i386 this is currently highly experimental and should be only
924 used for kernel development. It might also cause boot failures.
925 For x86_64 this is recommended on all multiprocessor Opteron systems.
926 If the system is EM64T, you should say N unless your system is
929 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
930 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
934 prompt "Old style AMD Opteron NUMA detection"
935 depends on X86_64 && NUMA && PCI
937 Enable K8 NUMA node topology detection. You should say Y here if
938 you have a multi processor AMD K8 system. This uses an old
939 method to read the NUMA configuration directly from the builtin
940 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
941 instead, which also takes priority if both are compiled in.
943 config X86_64_ACPI_NUMA
945 prompt "ACPI NUMA detection"
946 depends on X86_64 && NUMA && ACPI && PCI
949 Enable ACPI SRAT based node topology detection.
951 # Some NUMA nodes have memory ranges that span
952 # other nodes. Even though a pfn is valid and
953 # between a node's start and end pfns, it may not
954 # reside on that node. See memmap_init_zone()
956 config NODES_SPAN_OTHER_NODES
958 depends on X86_64_ACPI_NUMA
961 bool "NUMA emulation"
962 depends on X86_64 && NUMA
964 Enable NUMA emulation. A flat machine will be split
965 into virtual nodes when booted with "numa=fake=N", where N is the
966 number of nodes. This is only useful for debugging.
969 int "Max num nodes shift(1-15)"
971 default "6" if X86_64
972 default "4" if X86_NUMAQ
974 depends on NEED_MULTIPLE_NODES
976 config HAVE_ARCH_BOOTMEM_NODE
978 depends on X86_32 && NUMA
980 config ARCH_HAVE_MEMORY_PRESENT
982 depends on X86_32 && DISCONTIGMEM
984 config NEED_NODE_MEMMAP_SIZE
986 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
988 config HAVE_ARCH_ALLOC_REMAP
990 depends on X86_32 && NUMA
992 config ARCH_FLATMEM_ENABLE
994 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
996 config ARCH_DISCONTIGMEM_ENABLE
998 depends on NUMA && X86_32
1000 config ARCH_DISCONTIGMEM_DEFAULT
1002 depends on NUMA && X86_32
1004 config ARCH_SPARSEMEM_DEFAULT
1008 config ARCH_SPARSEMEM_ENABLE
1010 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1011 select SPARSEMEM_STATIC if X86_32
1012 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1014 config ARCH_SELECT_MEMORY_MODEL
1016 depends on ARCH_SPARSEMEM_ENABLE
1018 config ARCH_MEMORY_PROBE
1020 depends on MEMORY_HOTPLUG
1025 bool "Allocate 3rd-level pagetables from highmem"
1026 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1028 The VM uses one page table entry for each page of physical memory.
1029 For systems with a lot of RAM, this can be wasteful of precious
1030 low memory. Setting this option will put user-space page table
1031 entries in high memory.
1033 config MATH_EMULATION
1035 prompt "Math emulation" if X86_32
1037 Linux can emulate a math coprocessor (used for floating point
1038 operations) if you don't have one. 486DX and Pentium processors have
1039 a math coprocessor built in, 486SX and 386 do not, unless you added
1040 a 487DX or 387, respectively. (The messages during boot time can
1041 give you some hints here ["man dmesg"].) Everyone needs either a
1042 coprocessor or this emulation.
1044 If you don't have a math coprocessor, you need to say Y here; if you
1045 say Y here even though you have a coprocessor, the coprocessor will
1046 be used nevertheless. (This behavior can be changed with the kernel
1047 command line option "no387", which comes handy if your coprocessor
1048 is broken. Try "man bootparam" or see the documentation of your boot
1049 loader (lilo or loadlin) about how to pass options to the kernel at
1050 boot time.) This means that it is a good idea to say Y here if you
1051 intend to use this kernel on different machines.
1053 More information about the internals of the Linux math coprocessor
1054 emulation can be found in <file:arch/x86/math-emu/README>.
1056 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1057 kernel, it won't hurt.
1060 bool "MTRR (Memory Type Range Register) support"
1062 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1063 the Memory Type Range Registers (MTRRs) may be used to control
1064 processor access to memory ranges. This is most useful if you have
1065 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1066 allows bus write transfers to be combined into a larger transfer
1067 before bursting over the PCI/AGP bus. This can increase performance
1068 of image write operations 2.5 times or more. Saying Y here creates a
1069 /proc/mtrr file which may be used to manipulate your processor's
1070 MTRRs. Typically the X server should use this.
1072 This code has a reasonably generic interface so that similar
1073 control registers on other processors can be easily supported
1076 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1077 Registers (ARRs) which provide a similar functionality to MTRRs. For
1078 these, the ARRs are used to emulate the MTRRs.
1079 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1080 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1081 write-combining. All of these processors are supported by this code
1082 and it makes sense to say Y here if you have one of them.
1084 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1085 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1086 can lead to all sorts of problems, so it's good to say Y here.
1088 You can safely say Y even if your machine doesn't have MTRRs, you'll
1089 just add about 9 KB to your kernel.
1091 See <file:Documentation/mtrr.txt> for more information.
1093 config MTRR_SANITIZER
1095 prompt "MTRR cleanup support"
1098 Convert MTRR layout from continuous to discrete, so some X driver
1099 could add WB entries.
1101 Say N here if you see bootup problems (boot crash, boot hang,
1102 spontaneous reboots).
1104 Could be disabled with disable_mtrr_cleanup. Also mtrr_chunk_size
1105 could be used to send largest mtrr entry size for continuous block
1106 to hold holes (aka. UC entries)
1110 config MTRR_SANITIZER_ENABLE_DEFAULT
1111 int "MTRR cleanup enable value (0-1)"
1114 depends on MTRR_SANITIZER
1116 Enable mtrr cleanup default value
1118 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1119 int "MTRR cleanup spare reg num (0-7)"
1122 depends on MTRR_SANITIZER
1124 mtrr cleanup spare entries default, it can be changed via
1129 prompt "x86 PAT support"
1132 Use PAT attributes to setup page level cache control.
1134 PATs are the modern equivalents of MTRRs and are much more
1135 flexible than MTRRs.
1137 Say N here if you see bootup problems (boot crash, boot hang,
1138 spontaneous reboots) or a non-working video driver.
1144 prompt "EFI runtime service support"
1147 This enables the kernel to use EFI runtime services that are
1148 available (such as the EFI variable services).
1150 This option is only useful on systems that have EFI firmware.
1151 In addition, you should use the latest ELILO loader available
1152 at <http://elilo.sourceforge.net> in order to take advantage
1153 of EFI runtime services. However, even with this option, the
1154 resultant kernel should continue to boot on existing non-EFI
1159 prompt "Enable kernel irq balancing"
1160 depends on X86_32 && SMP && X86_IO_APIC
1162 The default yes will allow the kernel to do irq load balancing.
1163 Saying no will keep the kernel from doing irq load balancing.
1167 prompt "Enable seccomp to safely compute untrusted bytecode"
1170 This kernel feature is useful for number crunching applications
1171 that may need to compute untrusted bytecode during their
1172 execution. By using pipes or other transports made available to
1173 the process as file descriptors supporting the read/write
1174 syscalls, it's possible to isolate those applications in
1175 their own address space using seccomp. Once seccomp is
1176 enabled via /proc/<pid>/seccomp, it cannot be disabled
1177 and the task is only allowed to execute a few safe syscalls
1178 defined by each seccomp mode.
1180 If unsure, say Y. Only embedded should say N here.
1182 config CC_STACKPROTECTOR
1183 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1184 depends on X86_64 && EXPERIMENTAL && BROKEN
1186 This option turns on the -fstack-protector GCC feature. This
1187 feature puts, at the beginning of critical functions, a canary
1188 value on the stack just before the return address, and validates
1189 the value just before actually returning. Stack based buffer
1190 overflows (that need to overwrite this return address) now also
1191 overwrite the canary, which gets detected and the attack is then
1192 neutralized via a kernel panic.
1194 This feature requires gcc version 4.2 or above, or a distribution
1195 gcc with the feature backported. Older versions are automatically
1196 detected and for those versions, this configuration option is ignored.
1198 config CC_STACKPROTECTOR_ALL
1199 bool "Use stack-protector for all functions"
1200 depends on CC_STACKPROTECTOR
1202 Normally, GCC only inserts the canary value protection for
1203 functions that use large-ish on-stack buffers. By enabling
1204 this option, GCC will be asked to do this for ALL functions.
1206 source kernel/Kconfig.hz
1209 bool "kexec system call"
1210 depends on X86_BIOS_REBOOT
1212 kexec is a system call that implements the ability to shutdown your
1213 current kernel, and to start another kernel. It is like a reboot
1214 but it is independent of the system firmware. And like a reboot
1215 you can start any kernel with it, not just Linux.
1217 The name comes from the similarity to the exec system call.
1219 It is an ongoing process to be certain the hardware in a machine
1220 is properly shutdown, so do not be surprised if this code does not
1221 initially work for you. It may help to enable device hotplugging
1222 support. As of this writing the exact hardware interface is
1223 strongly in flux, so no good recommendation can be made.
1226 bool "kernel crash dumps (EXPERIMENTAL)"
1227 depends on EXPERIMENTAL
1228 depends on X86_64 || (X86_32 && HIGHMEM)
1230 Generate crash dump after being started by kexec.
1231 This should be normally only set in special crash dump kernels
1232 which are loaded in the main kernel with kexec-tools into
1233 a specially reserved region and then later executed after
1234 a crash by kdump/kexec. The crash dump kernel must be compiled
1235 to a memory address not used by the main kernel or BIOS using
1236 PHYSICAL_START, or it must be built as a relocatable image
1237 (CONFIG_RELOCATABLE=y).
1238 For more details see Documentation/kdump/kdump.txt
1240 config PHYSICAL_START
1241 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1242 default "0x1000000" if X86_NUMAQ
1243 default "0x200000" if X86_64
1246 This gives the physical address where the kernel is loaded.
1248 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1249 bzImage will decompress itself to above physical address and
1250 run from there. Otherwise, bzImage will run from the address where
1251 it has been loaded by the boot loader and will ignore above physical
1254 In normal kdump cases one does not have to set/change this option
1255 as now bzImage can be compiled as a completely relocatable image
1256 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1257 address. This option is mainly useful for the folks who don't want
1258 to use a bzImage for capturing the crash dump and want to use a
1259 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1260 to be specifically compiled to run from a specific memory area
1261 (normally a reserved region) and this option comes handy.
1263 So if you are using bzImage for capturing the crash dump, leave
1264 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1265 Otherwise if you plan to use vmlinux for capturing the crash dump
1266 change this value to start of the reserved region (Typically 16MB
1267 0x1000000). In other words, it can be set based on the "X" value as
1268 specified in the "crashkernel=YM@XM" command line boot parameter
1269 passed to the panic-ed kernel. Typically this parameter is set as
1270 crashkernel=64M@16M. Please take a look at
1271 Documentation/kdump/kdump.txt for more details about crash dumps.
1273 Usage of bzImage for capturing the crash dump is recommended as
1274 one does not have to build two kernels. Same kernel can be used
1275 as production kernel and capture kernel. Above option should have
1276 gone away after relocatable bzImage support is introduced. But it
1277 is present because there are users out there who continue to use
1278 vmlinux for dump capture. This option should go away down the
1281 Don't change this unless you know what you are doing.
1284 bool "Build a relocatable kernel (EXPERIMENTAL)"
1285 depends on EXPERIMENTAL
1287 This builds a kernel image that retains relocation information
1288 so it can be loaded someplace besides the default 1MB.
1289 The relocations tend to make the kernel binary about 10% larger,
1290 but are discarded at runtime.
1292 One use is for the kexec on panic case where the recovery kernel
1293 must live at a different physical address than the primary
1296 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1297 it has been loaded at and the compile time physical address
1298 (CONFIG_PHYSICAL_START) is ignored.
1300 config PHYSICAL_ALIGN
1302 prompt "Alignment value to which kernel should be aligned" if X86_32
1303 default "0x100000" if X86_32
1304 default "0x200000" if X86_64
1305 range 0x2000 0x400000
1307 This value puts the alignment restrictions on physical address
1308 where kernel is loaded and run from. Kernel is compiled for an
1309 address which meets above alignment restriction.
1311 If bootloader loads the kernel at a non-aligned address and
1312 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1313 address aligned to above value and run from there.
1315 If bootloader loads the kernel at a non-aligned address and
1316 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1317 load address and decompress itself to the address it has been
1318 compiled for and run from there. The address for which kernel is
1319 compiled already meets above alignment restrictions. Hence the
1320 end result is that kernel runs from a physical address meeting
1321 above alignment restrictions.
1323 Don't change this unless you know what you are doing.
1326 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1327 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1329 Say Y here to experiment with turning CPUs off and on, and to
1330 enable suspend on SMP systems. CPUs can be controlled through
1331 /sys/devices/system/cpu.
1332 Say N if you want to disable CPU hotplug and don't need to
1337 prompt "Compat VDSO support"
1338 depends on X86_32 || IA32_EMULATION
1340 Map the 32-bit VDSO to the predictable old-style address too.
1342 Say N here if you are running a sufficiently recent glibc
1343 version (2.3.3 or later), to remove the high-mapped
1344 VDSO mapping and to exclusively use the randomized VDSO.
1350 config ARCH_ENABLE_MEMORY_HOTPLUG
1352 depends on X86_64 || (X86_32 && HIGHMEM)
1354 config HAVE_ARCH_EARLY_PFN_TO_NID
1358 menu "Power management options"
1359 depends on !X86_VOYAGER
1361 config ARCH_HIBERNATION_HEADER
1363 depends on X86_64 && HIBERNATION
1365 source "kernel/power/Kconfig"
1367 source "drivers/acpi/Kconfig"
1372 depends on APM || APM_MODULE
1375 tristate "APM (Advanced Power Management) BIOS support"
1376 depends on X86_32 && PM_SLEEP && !X86_VISWS
1378 APM is a BIOS specification for saving power using several different
1379 techniques. This is mostly useful for battery powered laptops with
1380 APM compliant BIOSes. If you say Y here, the system time will be
1381 reset after a RESUME operation, the /proc/apm device will provide
1382 battery status information, and user-space programs will receive
1383 notification of APM "events" (e.g. battery status change).
1385 If you select "Y" here, you can disable actual use of the APM
1386 BIOS by passing the "apm=off" option to the kernel at boot time.
1388 Note that the APM support is almost completely disabled for
1389 machines with more than one CPU.
1391 In order to use APM, you will need supporting software. For location
1392 and more information, read <file:Documentation/power/pm.txt> and the
1393 Battery Powered Linux mini-HOWTO, available from
1394 <http://www.tldp.org/docs.html#howto>.
1396 This driver does not spin down disk drives (see the hdparm(8)
1397 manpage ("man 8 hdparm") for that), and it doesn't turn off
1398 VESA-compliant "green" monitors.
1400 This driver does not support the TI 4000M TravelMate and the ACER
1401 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1402 desktop machines also don't have compliant BIOSes, and this driver
1403 may cause those machines to panic during the boot phase.
1405 Generally, if you don't have a battery in your machine, there isn't
1406 much point in using this driver and you should say N. If you get
1407 random kernel OOPSes or reboots that don't seem to be related to
1408 anything, try disabling/enabling this option (or disabling/enabling
1411 Some other things you should try when experiencing seemingly random,
1414 1) make sure that you have enough swap space and that it is
1416 2) pass the "no-hlt" option to the kernel
1417 3) switch on floating point emulation in the kernel and pass
1418 the "no387" option to the kernel
1419 4) pass the "floppy=nodma" option to the kernel
1420 5) pass the "mem=4M" option to the kernel (thereby disabling
1421 all but the first 4 MB of RAM)
1422 6) make sure that the CPU is not over clocked.
1423 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1424 8) disable the cache from your BIOS settings
1425 9) install a fan for the video card or exchange video RAM
1426 10) install a better fan for the CPU
1427 11) exchange RAM chips
1428 12) exchange the motherboard.
1430 To compile this driver as a module, choose M here: the
1431 module will be called apm.
1435 config APM_IGNORE_USER_SUSPEND
1436 bool "Ignore USER SUSPEND"
1438 This option will ignore USER SUSPEND requests. On machines with a
1439 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1440 series notebooks, it is necessary to say Y because of a BIOS bug.
1442 config APM_DO_ENABLE
1443 bool "Enable PM at boot time"
1445 Enable APM features at boot time. From page 36 of the APM BIOS
1446 specification: "When disabled, the APM BIOS does not automatically
1447 power manage devices, enter the Standby State, enter the Suspend
1448 State, or take power saving steps in response to CPU Idle calls."
1449 This driver will make CPU Idle calls when Linux is idle (unless this
1450 feature is turned off -- see "Do CPU IDLE calls", below). This
1451 should always save battery power, but more complicated APM features
1452 will be dependent on your BIOS implementation. You may need to turn
1453 this option off if your computer hangs at boot time when using APM
1454 support, or if it beeps continuously instead of suspending. Turn
1455 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1456 T400CDT. This is off by default since most machines do fine without
1460 bool "Make CPU Idle calls when idle"
1462 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1463 On some machines, this can activate improved power savings, such as
1464 a slowed CPU clock rate, when the machine is idle. These idle calls
1465 are made after the idle loop has run for some length of time (e.g.,
1466 333 mS). On some machines, this will cause a hang at boot time or
1467 whenever the CPU becomes idle. (On machines with more than one CPU,
1468 this option does nothing.)
1470 config APM_DISPLAY_BLANK
1471 bool "Enable console blanking using APM"
1473 Enable console blanking using the APM. Some laptops can use this to
1474 turn off the LCD backlight when the screen blanker of the Linux
1475 virtual console blanks the screen. Note that this is only used by
1476 the virtual console screen blanker, and won't turn off the backlight
1477 when using the X Window system. This also doesn't have anything to
1478 do with your VESA-compliant power-saving monitor. Further, this
1479 option doesn't work for all laptops -- it might not turn off your
1480 backlight at all, or it might print a lot of errors to the console,
1481 especially if you are using gpm.
1483 config APM_ALLOW_INTS
1484 bool "Allow interrupts during APM BIOS calls"
1486 Normally we disable external interrupts while we are making calls to
1487 the APM BIOS as a measure to lessen the effects of a badly behaving
1488 BIOS implementation. The BIOS should reenable interrupts if it
1489 needs to. Unfortunately, some BIOSes do not -- especially those in
1490 many of the newer IBM Thinkpads. If you experience hangs when you
1491 suspend, try setting this to Y. Otherwise, say N.
1493 config APM_REAL_MODE_POWER_OFF
1494 bool "Use real mode APM BIOS call to power off"
1496 Use real mode APM BIOS calls to switch off the computer. This is
1497 a work-around for a number of buggy BIOSes. Switch this option on if
1498 your computer crashes instead of powering off properly.
1502 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1504 source "drivers/cpuidle/Kconfig"
1509 menu "Bus options (PCI etc.)"
1512 bool "PCI support" if !X86_VISWS && !X86_VSMP
1513 depends on !X86_VOYAGER
1515 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1517 Find out whether you have a PCI motherboard. PCI is the name of a
1518 bus system, i.e. the way the CPU talks to the other stuff inside
1519 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1520 VESA. If you have PCI, say Y, otherwise N.
1523 prompt "PCI access mode"
1524 depends on X86_32 && PCI && !X86_VISWS
1527 On PCI systems, the BIOS can be used to detect the PCI devices and
1528 determine their configuration. However, some old PCI motherboards
1529 have BIOS bugs and may crash if this is done. Also, some embedded
1530 PCI-based systems don't have any BIOS at all. Linux can also try to
1531 detect the PCI hardware directly without using the BIOS.
1533 With this option, you can specify how Linux should detect the
1534 PCI devices. If you choose "BIOS", the BIOS will be used,
1535 if you choose "Direct", the BIOS won't be used, and if you
1536 choose "MMConfig", then PCI Express MMCONFIG will be used.
1537 If you choose "Any", the kernel will try MMCONFIG, then the
1538 direct access method and falls back to the BIOS if that doesn't
1539 work. If unsure, go with the default, which is "Any".
1544 config PCI_GOMMCONFIG
1561 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1563 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1566 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC) || X86_VISWS)
1570 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1574 depends on PCI && PCI_GOOLPC
1582 bool "Support mmconfig PCI config space access"
1583 depends on X86_64 && PCI && ACPI
1586 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1587 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1589 DMA remapping (DMAR) devices support enables independent address
1590 translations for Direct Memory Access (DMA) from devices.
1591 These DMA remapping devices are reported via ACPI tables
1592 and include PCI device scope covered by these DMA
1597 prompt "Support for Graphics workaround"
1600 Current Graphics drivers tend to use physical address
1601 for DMA and avoid using DMA APIs. Setting this config
1602 option permits the IOMMU driver to set a unity map for
1603 all the OS-visible memory. Hence the driver can continue
1604 to use physical addresses for DMA.
1606 config DMAR_FLOPPY_WA
1610 Floppy disk drivers are know to bypass DMA API calls
1611 thereby failing to work when IOMMU is enabled. This
1612 workaround will setup a 1:1 mapping for the first
1613 16M to make floppy (an ISA device) work.
1615 source "drivers/pci/pcie/Kconfig"
1617 source "drivers/pci/Kconfig"
1619 # x86_64 have no ISA slots, but do have ISA-style DMA.
1627 depends on !(X86_VOYAGER || X86_VISWS)
1629 Find out whether you have ISA slots on your motherboard. ISA is the
1630 name of a bus system, i.e. the way the CPU talks to the other stuff
1631 inside your box. Other bus systems are PCI, EISA, MicroChannel
1632 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1633 newer boards don't support it. If you have ISA, say Y, otherwise N.
1639 The Extended Industry Standard Architecture (EISA) bus was
1640 developed as an open alternative to the IBM MicroChannel bus.
1642 The EISA bus provided some of the features of the IBM MicroChannel
1643 bus while maintaining backward compatibility with cards made for
1644 the older ISA bus. The EISA bus saw limited use between 1988 and
1645 1995 when it was made obsolete by the PCI bus.
1647 Say Y here if you are building a kernel for an EISA-based machine.
1651 source "drivers/eisa/Kconfig"
1654 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1655 default y if X86_VOYAGER
1657 MicroChannel Architecture is found in some IBM PS/2 machines and
1658 laptops. It is a bus system similar to PCI or ISA. See
1659 <file:Documentation/mca.txt> (and especially the web page given
1660 there) before attempting to build an MCA bus kernel.
1662 source "drivers/mca/Kconfig"
1665 tristate "NatSemi SCx200 support"
1666 depends on !X86_VOYAGER
1668 This provides basic support for National Semiconductor's
1669 (now AMD's) Geode processors. The driver probes for the
1670 PCI-IDs of several on-chip devices, so its a good dependency
1671 for other scx200_* drivers.
1673 If compiled as a module, the driver is named scx200.
1675 config SCx200HR_TIMER
1676 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1677 depends on SCx200 && GENERIC_TIME
1680 This driver provides a clocksource built upon the on-chip
1681 27MHz high-resolution timer. Its also a workaround for
1682 NSC Geode SC-1100's buggy TSC, which loses time when the
1683 processor goes idle (as is done by the scheduler). The
1684 other workaround is idle=poll boot option.
1686 config GEODE_MFGPT_TIMER
1688 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1689 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1691 This driver provides a clock event source based on the MFGPT
1692 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1693 MFGPTs have a better resolution and max interval than the
1694 generic PIT, and are suitable for use as high-res timers.
1697 bool "One Laptop Per Child support"
1700 Add support for detecting the unique features of the OLPC
1707 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1709 source "drivers/pcmcia/Kconfig"
1711 source "drivers/pci/hotplug/Kconfig"
1716 menu "Executable file formats / Emulations"
1718 source "fs/Kconfig.binfmt"
1720 config IA32_EMULATION
1721 bool "IA32 Emulation"
1723 select COMPAT_BINFMT_ELF
1725 Include code to run 32-bit programs under a 64-bit kernel. You should
1726 likely turn this on, unless you're 100% sure that you don't have any
1727 32-bit programs left.
1730 tristate "IA32 a.out support"
1731 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1733 Support old a.out binaries in the 32bit emulation.
1737 depends on IA32_EMULATION
1739 config COMPAT_FOR_U64_ALIGNMENT
1743 config SYSVIPC_COMPAT
1745 depends on X86_64 && COMPAT && SYSVIPC
1750 source "net/Kconfig"
1752 source "drivers/Kconfig"
1754 source "drivers/firmware/Kconfig"
1758 source "arch/x86/Kconfig.debug"
1760 source "security/Kconfig"
1762 source "crypto/Kconfig"
1764 source "arch/x86/kvm/Kconfig"
1766 source "lib/Kconfig"