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
31 default "arch/x86/configs/i386_defconfig" if X86_32
32 default "arch/x86/configs/x86_64_defconfig" if X86_64
35 config GENERIC_LOCKBREAK
41 config GENERIC_CMOS_UPDATE
44 config CLOCKSOURCE_WATCHDOG
47 config GENERIC_CLOCKEVENTS
50 config GENERIC_CLOCKEVENTS_BROADCAST
52 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
54 config LOCKDEP_SUPPORT
57 config STACKTRACE_SUPPORT
60 config HAVE_LATENCYTOP_SUPPORT
63 config FAST_CMPXCHG_LOCAL
76 config GENERIC_ISA_DMA
86 config GENERIC_HWEIGHT
92 config ARCH_MAY_HAVE_PC_FDC
95 config RWSEM_GENERIC_SPINLOCK
98 config RWSEM_XCHGADD_ALGORITHM
101 config ARCH_HAS_ILOG2_U32
104 config ARCH_HAS_ILOG2_U64
107 config ARCH_HAS_CPU_IDLE_WAIT
110 config GENERIC_CALIBRATE_DELAY
113 config GENERIC_TIME_VSYSCALL
117 config ARCH_HAS_CPU_RELAX
120 config ARCH_HAS_CACHE_LINE_SIZE
123 config HAVE_SETUP_PER_CPU_AREA
124 def_bool X86_64 || (X86_SMP && !X86_VOYAGER)
126 config HAVE_CPUMASK_OF_CPU_MAP
129 config ARCH_HIBERNATION_POSSIBLE
131 depends on !SMP || !X86_VOYAGER
133 config ARCH_SUSPEND_POSSIBLE
135 depends on !X86_VOYAGER
141 config ARCH_POPULATES_NODE_MAP
148 config ARCH_SUPPORTS_AOUT
151 config ARCH_SUPPORTS_OPTIMIZED_INLINING
154 # Use the generic interrupt handling code in kernel/irq/:
155 config GENERIC_HARDIRQS
159 config GENERIC_IRQ_PROBE
163 config GENERIC_PENDING_IRQ
165 depends on GENERIC_HARDIRQS && SMP
170 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
175 depends on X86_32 && SMP
179 depends on X86_64 && SMP
184 depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || X86_64
187 config X86_BIOS_REBOOT
189 depends on !X86_VISWS && !X86_VOYAGER
192 config X86_TRAMPOLINE
194 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
199 source "init/Kconfig"
201 menu "Processor type and features"
203 source "kernel/time/Kconfig"
206 bool "Symmetric multi-processing support"
208 This enables support for systems with more than one CPU. If you have
209 a system with only one CPU, like most personal computers, say N. If
210 you have a system with more than one CPU, say Y.
212 If you say N here, the kernel will run on single and multiprocessor
213 machines, but will use only one CPU of a multiprocessor machine. If
214 you say Y here, the kernel will run on many, but not all,
215 singleprocessor machines. On a singleprocessor machine, the kernel
216 will run faster if you say N here.
218 Note that if you say Y here and choose architecture "586" or
219 "Pentium" under "Processor family", the kernel will not work on 486
220 architectures. Similarly, multiprocessor kernels for the "PPro"
221 architecture may not work on all Pentium based boards.
223 People using multiprocessor machines who say Y here should also say
224 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
225 Management" code will be disabled if you say Y here.
227 See also <file:Documentation/i386/IO-APIC.txt>,
228 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
229 <http://www.tldp.org/docs.html#howto>.
231 If you don't know what to do here, say N.
234 prompt "Subarchitecture Type"
240 Choose this option if your computer is a standard PC or compatible.
246 Select this for an AMD Elan processor.
248 Do not use this option for K6/Athlon/Opteron processors!
250 If unsure, choose "PC-compatible" instead.
254 depends on X86_32 && (SMP || BROKEN)
256 Voyager is an MCA-based 32-way capable SMP architecture proprietary
257 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
261 If you do not specifically know you have a Voyager based machine,
262 say N here, otherwise the kernel you build will not be bootable.
265 bool "SGI 320/540 (Visual Workstation)"
268 The SGI Visual Workstation series is an IA32-based workstation
269 based on SGI systems chips with some legacy PC hardware attached.
271 Say Y here to create a kernel to run on the SGI 320 or 540.
273 A kernel compiled for the Visual Workstation will not run on PCs
274 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
276 config X86_GENERICARCH
277 bool "Generic architecture"
280 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
281 subarchitectures. It is intended for a generic binary kernel.
282 if you select them all, kernel will probe it one by one. and will
288 bool "NUMAQ (IBM/Sequent)"
289 depends on SMP && X86_32
292 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
293 NUMA multiquad box. This changes the way that processors are
294 bootstrapped, and uses Clustered Logical APIC addressing mode instead
295 of Flat Logical. You will need a new lynxer.elf file to flash your
296 firmware with - send email to <Martin.Bligh@us.ibm.com>.
299 bool "Summit/EXA (IBM x440)"
300 depends on X86_32 && SMP
302 This option is needed for IBM systems that use the Summit/EXA chipset.
303 In particular, it is needed for the x440.
306 bool "Support for Unisys ES7000 IA32 series"
307 depends on X86_32 && SMP
309 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
310 supposed to run on an IA32-based Unisys ES7000 system.
313 bool "Support for big SMP systems with more than 8 CPUs"
314 depends on X86_32 && SMP
316 This option is needed for the systems that have more than 8 CPUs
317 and if the system is not of any sub-arch type above.
322 bool "RDC R-321x SoC"
325 select X86_REBOOTFIXUPS
331 This option is needed for RDC R-321x system-on-chip, also known
333 If you don't have one of these chips, you should say N here.
336 bool "Support for ScaleMP vSMP"
340 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
341 supposed to run on these EM64T-based machines. Only choose this option
342 if you have one of these machines.
346 config SCHED_NO_NO_OMIT_FRAME_POINTER
348 prompt "Single-depth WCHAN output"
351 Calculate simpler /proc/<PID>/wchan values. If this option
352 is disabled then wchan values will recurse back to the
353 caller function. This provides more accurate wchan values,
354 at the expense of slightly more scheduling overhead.
356 If in doubt, say "Y".
358 menuconfig PARAVIRT_GUEST
359 bool "Paravirtualized guest support"
361 Say Y here to get to see options related to running Linux under
362 various hypervisors. This option alone does not add any kernel code.
364 If you say N, all options in this submenu will be skipped and disabled.
368 source "arch/x86/xen/Kconfig"
371 bool "VMI Guest support"
374 depends on !(X86_VISWS || X86_VOYAGER)
376 VMI provides a paravirtualized interface to the VMware ESX server
377 (it could be used by other hypervisors in theory too, but is not
378 at the moment), by linking the kernel to a GPL-ed ROM module
379 provided by the hypervisor.
382 bool "KVM paravirtualized clock"
384 select PARAVIRT_CLOCK
385 depends on !(X86_VISWS || X86_VOYAGER)
387 Turning on this option will allow you to run a paravirtualized clock
388 when running over the KVM hypervisor. Instead of relying on a PIT
389 (or probably other) emulation by the underlying device model, the host
390 provides the guest with timing infrastructure such as time of day, and
394 bool "KVM Guest support"
396 depends on !(X86_VISWS || X86_VOYAGER)
398 This option enables various optimizations for running under the KVM
401 source "arch/x86/lguest/Kconfig"
404 bool "Enable paravirtualization code"
405 depends on !(X86_VISWS || X86_VOYAGER)
407 This changes the kernel so it can modify itself when it is run
408 under a hypervisor, potentially improving performance significantly
409 over full virtualization. However, when run without a hypervisor
410 the kernel is theoretically slower and slightly larger.
412 config PARAVIRT_CLOCK
418 config MEMTEST_BOOTPARAM
419 bool "Memtest boot parameter"
423 This option adds a kernel parameter 'memtest', which allows memtest
424 to be disabled at boot. If this option is selected, memtest
425 functionality can be disabled with memtest=0 on the kernel
426 command line. The purpose of this option is to allow a single
427 kernel image to be distributed with memtest built in, but not
430 If you are unsure how to answer this question, answer Y.
432 config MEMTEST_BOOTPARAM_VALUE
433 int "Memtest boot parameter default value (0-4)"
434 depends on MEMTEST_BOOTPARAM
438 This option sets the default value for the kernel parameter
439 'memtest', which allows memtest to be disabled at boot. If this
440 option is set to 0 (zero), the memtest kernel parameter will
441 default to 0, disabling memtest at bootup. If this option is
442 set to 4, the memtest kernel parameter will default to 4,
443 enabling memtest at bootup, and use that as pattern number.
445 If you are unsure how to answer this question, answer 0.
449 depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
452 config HAVE_ARCH_PARSE_SRAT
456 config X86_SUMMIT_NUMA
458 depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
460 config X86_CYCLONE_TIMER
462 depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
464 config ES7000_CLUSTERED_APIC
466 depends on SMP && X86_ES7000 && MPENTIUMIII
468 source "arch/x86/Kconfig.cpu"
472 prompt "HPET Timer Support" if X86_32
474 Use the IA-PC HPET (High Precision Event Timer) to manage
475 time in preference to the PIT and RTC, if a HPET is
477 HPET is the next generation timer replacing legacy 8254s.
478 The HPET provides a stable time base on SMP
479 systems, unlike the TSC, but it is more expensive to access,
480 as it is off-chip. You can find the HPET spec at
481 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
483 You can safely choose Y here. However, HPET will only be
484 activated if the platform and the BIOS support this feature.
485 Otherwise the 8254 will be used for timing services.
487 Choose N to continue using the legacy 8254 timer.
489 config HPET_EMULATE_RTC
491 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
493 # Mark as embedded because too many people got it wrong.
494 # The code disables itself when not needed.
497 bool "Enable DMI scanning" if EMBEDDED
499 Enabled scanning of DMI to identify machine quirks. Say Y
500 here unless you have verified that your setup is not
501 affected by entries in the DMI blacklist. Required by PNP
505 bool "GART IOMMU support" if EMBEDDED
509 depends on X86_64 && PCI
511 Support for full DMA access of devices with 32bit memory access only
512 on systems with more than 3GB. This is usually needed for USB,
513 sound, many IDE/SATA chipsets and some other devices.
514 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
515 based hardware IOMMU and a software bounce buffer based IOMMU used
516 on Intel systems and as fallback.
517 The code is only active when needed (enough memory and limited
518 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
522 bool "IBM Calgary IOMMU support"
524 depends on X86_64 && PCI && EXPERIMENTAL
526 Support for hardware IOMMUs in IBM's xSeries x366 and x460
527 systems. Needed to run systems with more than 3GB of memory
528 properly with 32-bit PCI devices that do not support DAC
529 (Double Address Cycle). Calgary also supports bus level
530 isolation, where all DMAs pass through the IOMMU. This
531 prevents them from going anywhere except their intended
532 destination. This catches hard-to-find kernel bugs and
533 mis-behaving drivers and devices that do not use the DMA-API
534 properly to set up their DMA buffers. The IOMMU can be
535 turned off at boot time with the iommu=off parameter.
536 Normally the kernel will make the right choice by itself.
539 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
541 prompt "Should Calgary be enabled by default?"
542 depends on CALGARY_IOMMU
544 Should Calgary be enabled by default? if you choose 'y', Calgary
545 will be used (if it exists). If you choose 'n', Calgary will not be
546 used even if it exists. If you choose 'n' and would like to use
547 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
550 # need this always selected by IOMMU for the VIA workaround
554 Support for software bounce buffers used on x86-64 systems
555 which don't have a hardware IOMMU (e.g. the current generation
556 of Intel's x86-64 CPUs). Using this PCI devices which can only
557 access 32-bits of memory can be used on systems with more than
558 3 GB of memory. If unsure, say Y.
561 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB)
564 int "Maximum number of CPUs (2-255)"
567 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
570 This allows you to specify the maximum number of CPUs which this
571 kernel will support. The maximum supported value is 255 and the
572 minimum value which makes sense is 2.
574 This is purely to save memory - each supported CPU adds
575 approximately eight kilobytes to the kernel image.
578 bool "SMT (Hyperthreading) scheduler support"
581 SMT scheduler support improves the CPU scheduler's decision making
582 when dealing with Intel Pentium 4 chips with HyperThreading at a
583 cost of slightly increased overhead in some places. If unsure say
588 prompt "Multi-core scheduler support"
591 Multi-core scheduler support improves the CPU scheduler's decision
592 making when dealing with multi-core CPU chips at a cost of slightly
593 increased overhead in some places. If unsure say N here.
595 source "kernel/Kconfig.preempt"
598 bool "Local APIC support on uniprocessors"
599 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
601 A local APIC (Advanced Programmable Interrupt Controller) is an
602 integrated interrupt controller in the CPU. If you have a single-CPU
603 system which has a processor with a local APIC, you can say Y here to
604 enable and use it. If you say Y here even though your machine doesn't
605 have a local APIC, then the kernel will still run with no slowdown at
606 all. The local APIC supports CPU-generated self-interrupts (timer,
607 performance counters), and the NMI watchdog which detects hard
611 bool "IO-APIC support on uniprocessors"
612 depends on X86_UP_APIC
614 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
615 SMP-capable replacement for PC-style interrupt controllers. Most
616 SMP systems and many recent uniprocessor systems have one.
618 If you have a single-CPU system with an IO-APIC, you can say Y here
619 to use it. If you say Y here even though your machine doesn't have
620 an IO-APIC, then the kernel will still run with no slowdown at all.
622 config X86_LOCAL_APIC
624 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
628 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
630 config X86_VISWS_APIC
632 depends on X86_32 && X86_VISWS
635 bool "Machine Check Exception"
636 depends on !X86_VOYAGER
638 Machine Check Exception support allows the processor to notify the
639 kernel if it detects a problem (e.g. overheating, component failure).
640 The action the kernel takes depends on the severity of the problem,
641 ranging from a warning message on the console, to halting the machine.
642 Your processor must be a Pentium or newer to support this - check the
643 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
644 have a design flaw which leads to false MCE events - hence MCE is
645 disabled on all P5 processors, unless explicitly enabled with "mce"
646 as a boot argument. Similarly, if MCE is built in and creates a
647 problem on some new non-standard machine, you can boot with "nomce"
648 to disable it. MCE support simply ignores non-MCE processors like
649 the 386 and 486, so nearly everyone can say Y here.
653 prompt "Intel MCE features"
654 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
656 Additional support for intel specific MCE features such as
661 prompt "AMD MCE features"
662 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
664 Additional support for AMD specific MCE features such as
665 the DRAM Error Threshold.
667 config X86_MCE_NONFATAL
668 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
669 depends on X86_32 && X86_MCE
671 Enabling this feature starts a timer that triggers every 5 seconds which
672 will look at the machine check registers to see if anything happened.
673 Non-fatal problems automatically get corrected (but still logged).
674 Disable this if you don't want to see these messages.
675 Seeing the messages this option prints out may be indicative of dying
676 or out-of-spec (ie, overclocked) hardware.
677 This option only does something on certain CPUs.
678 (AMD Athlon/Duron and Intel Pentium 4)
680 config X86_MCE_P4THERMAL
681 bool "check for P4 thermal throttling interrupt."
682 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
684 Enabling this feature will cause a message to be printed when the P4
685 enters thermal throttling.
688 bool "Enable VM86 support" if EMBEDDED
692 This option is required by programs like DOSEMU to run 16-bit legacy
693 code on X86 processors. It also may be needed by software like
694 XFree86 to initialize some video cards via BIOS. Disabling this
695 option saves about 6k.
698 tristate "Toshiba Laptop support"
701 This adds a driver to safely access the System Management Mode of
702 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
703 not work on models with a Phoenix BIOS. The System Management Mode
704 is used to set the BIOS and power saving options on Toshiba portables.
706 For information on utilities to make use of this driver see the
707 Toshiba Linux utilities web site at:
708 <http://www.buzzard.org.uk/toshiba/>.
710 Say Y if you intend to run this kernel on a Toshiba portable.
714 tristate "Dell laptop support"
716 This adds a driver to safely access the System Management Mode
717 of the CPU on the Dell Inspiron 8000. The System Management Mode
718 is used to read cpu temperature and cooling fan status and to
719 control the fans on the I8K portables.
721 This driver has been tested only on the Inspiron 8000 but it may
722 also work with other Dell laptops. You can force loading on other
723 models by passing the parameter `force=1' to the module. Use at
726 For information on utilities to make use of this driver see the
727 I8K Linux utilities web site at:
728 <http://people.debian.org/~dz/i8k/>
730 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
733 config X86_REBOOTFIXUPS
735 prompt "Enable X86 board specific fixups for reboot"
736 depends on X86_32 && X86
738 This enables chipset and/or board specific fixups to be done
739 in order to get reboot to work correctly. This is only needed on
740 some combinations of hardware and BIOS. The symptom, for which
741 this config is intended, is when reboot ends with a stalled/hung
744 Currently, the only fixup is for the Geode machines using
745 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
747 Say Y if you want to enable the fixup. Currently, it's safe to
748 enable this option even if you don't need it.
752 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
755 If you say Y here, you will be able to update the microcode on
756 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
757 Pentium III, Pentium 4, Xeon etc. You will obviously need the
758 actual microcode binary data itself which is not shipped with the
761 For latest news and information on obtaining all the required
762 ingredients for this driver, check:
763 <http://www.urbanmyth.org/microcode/>.
765 To compile this driver as a module, choose M here: the
766 module will be called microcode.
768 config MICROCODE_OLD_INTERFACE
773 tristate "/dev/cpu/*/msr - Model-specific register support"
775 This device gives privileged processes access to the x86
776 Model-Specific Registers (MSRs). It is a character device with
777 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
778 MSR accesses are directed to a specific CPU on multi-processor
782 tristate "/dev/cpu/*/cpuid - CPU information support"
784 This device gives processes access to the x86 CPUID instruction to
785 be executed on a specific processor. It is a character device
786 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
790 prompt "High Memory Support"
791 default HIGHMEM4G if !X86_NUMAQ
792 default HIGHMEM64G if X86_NUMAQ
797 depends on !X86_NUMAQ
799 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
800 However, the address space of 32-bit x86 processors is only 4
801 Gigabytes large. That means that, if you have a large amount of
802 physical memory, not all of it can be "permanently mapped" by the
803 kernel. The physical memory that's not permanently mapped is called
806 If you are compiling a kernel which will never run on a machine with
807 more than 1 Gigabyte total physical RAM, answer "off" here (default
808 choice and suitable for most users). This will result in a "3GB/1GB"
809 split: 3GB are mapped so that each process sees a 3GB virtual memory
810 space and the remaining part of the 4GB virtual memory space is used
811 by the kernel to permanently map as much physical memory as
814 If the machine has between 1 and 4 Gigabytes physical RAM, then
817 If more than 4 Gigabytes is used then answer "64GB" here. This
818 selection turns Intel PAE (Physical Address Extension) mode on.
819 PAE implements 3-level paging on IA32 processors. PAE is fully
820 supported by Linux, PAE mode is implemented on all recent Intel
821 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
822 then the kernel will not boot on CPUs that don't support PAE!
824 The actual amount of total physical memory will either be
825 auto detected or can be forced by using a kernel command line option
826 such as "mem=256M". (Try "man bootparam" or see the documentation of
827 your boot loader (lilo or loadlin) about how to pass options to the
828 kernel at boot time.)
830 If unsure, say "off".
834 depends on !X86_NUMAQ
836 Select this if you have a 32-bit processor and between 1 and 4
837 gigabytes of physical RAM.
841 depends on !M386 && !M486
844 Select this if you have a 32-bit processor and more than 4
845 gigabytes of physical RAM.
850 depends on EXPERIMENTAL
851 prompt "Memory split" if EMBEDDED
855 Select the desired split between kernel and user memory.
857 If the address range available to the kernel is less than the
858 physical memory installed, the remaining memory will be available
859 as "high memory". Accessing high memory is a little more costly
860 than low memory, as it needs to be mapped into the kernel first.
861 Note that increasing the kernel address space limits the range
862 available to user programs, making the address space there
863 tighter. Selecting anything other than the default 3G/1G split
864 will also likely make your kernel incompatible with binary-only
867 If you are not absolutely sure what you are doing, leave this
871 bool "3G/1G user/kernel split"
872 config VMSPLIT_3G_OPT
874 bool "3G/1G user/kernel split (for full 1G low memory)"
876 bool "2G/2G user/kernel split"
877 config VMSPLIT_2G_OPT
879 bool "2G/2G user/kernel split (for full 2G low memory)"
881 bool "1G/3G user/kernel split"
886 default 0xB0000000 if VMSPLIT_3G_OPT
887 default 0x80000000 if VMSPLIT_2G
888 default 0x78000000 if VMSPLIT_2G_OPT
889 default 0x40000000 if VMSPLIT_1G
895 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
899 prompt "PAE (Physical Address Extension) Support"
900 depends on X86_32 && !HIGHMEM4G
901 select RESOURCES_64BIT
903 PAE is required for NX support, and furthermore enables
904 larger swapspace support for non-overcommit purposes. It
905 has the cost of more pagetable lookup overhead, and also
906 consumes more pagetable space per process.
908 # Common NUMA Features
910 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
912 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || X86_SUMMIT && ACPI) && EXPERIMENTAL)
914 default y if (X86_NUMAQ || X86_SUMMIT || X86_GENERICARCH)
916 Enable NUMA (Non Uniform Memory Access) support.
917 The kernel will try to allocate memory used by a CPU on the
918 local memory controller of the CPU and add some more
919 NUMA awareness to the kernel.
921 For i386 this is currently highly experimental and should be only
922 used for kernel development. It might also cause boot failures.
923 For x86_64 this is recommended on all multiprocessor Opteron systems.
924 If the system is EM64T, you should say N unless your system is
927 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
928 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
932 prompt "Old style AMD Opteron NUMA detection"
933 depends on X86_64 && NUMA && PCI
935 Enable K8 NUMA node topology detection. You should say Y here if
936 you have a multi processor AMD K8 system. This uses an old
937 method to read the NUMA configuration directly from the builtin
938 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
939 instead, which also takes priority if both are compiled in.
941 config X86_64_ACPI_NUMA
943 prompt "ACPI NUMA detection"
944 depends on X86_64 && NUMA && ACPI && PCI
947 Enable ACPI SRAT based node topology detection.
949 # Some NUMA nodes have memory ranges that span
950 # other nodes. Even though a pfn is valid and
951 # between a node's start and end pfns, it may not
952 # reside on that node. See memmap_init_zone()
954 config NODES_SPAN_OTHER_NODES
956 depends on X86_64_ACPI_NUMA
959 bool "NUMA emulation"
960 depends on X86_64 && NUMA
962 Enable NUMA emulation. A flat machine will be split
963 into virtual nodes when booted with "numa=fake=N", where N is the
964 number of nodes. This is only useful for debugging.
967 int "Max num nodes shift(1-9)"
969 default "6" if X86_64
970 default "4" if X86_NUMAQ
972 depends on NEED_MULTIPLE_NODES
974 config HAVE_ARCH_BOOTMEM_NODE
976 depends on X86_32 && NUMA
978 config ARCH_HAVE_MEMORY_PRESENT
980 depends on X86_32 && DISCONTIGMEM
982 config NEED_NODE_MEMMAP_SIZE
984 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
986 config HAVE_ARCH_ALLOC_REMAP
988 depends on X86_32 && NUMA
990 config ARCH_FLATMEM_ENABLE
992 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
994 config ARCH_DISCONTIGMEM_ENABLE
996 depends on NUMA && X86_32
998 config ARCH_DISCONTIGMEM_DEFAULT
1000 depends on NUMA && X86_32
1002 config ARCH_SPARSEMEM_DEFAULT
1006 config ARCH_SPARSEMEM_ENABLE
1008 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1009 select SPARSEMEM_STATIC if X86_32
1010 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1012 config ARCH_SELECT_MEMORY_MODEL
1014 depends on ARCH_SPARSEMEM_ENABLE
1016 config ARCH_MEMORY_PROBE
1018 depends on MEMORY_HOTPLUG
1023 bool "Allocate 3rd-level pagetables from highmem"
1024 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1026 The VM uses one page table entry for each page of physical memory.
1027 For systems with a lot of RAM, this can be wasteful of precious
1028 low memory. Setting this option will put user-space page table
1029 entries in high memory.
1031 config MATH_EMULATION
1033 prompt "Math emulation" if X86_32
1035 Linux can emulate a math coprocessor (used for floating point
1036 operations) if you don't have one. 486DX and Pentium processors have
1037 a math coprocessor built in, 486SX and 386 do not, unless you added
1038 a 487DX or 387, respectively. (The messages during boot time can
1039 give you some hints here ["man dmesg"].) Everyone needs either a
1040 coprocessor or this emulation.
1042 If you don't have a math coprocessor, you need to say Y here; if you
1043 say Y here even though you have a coprocessor, the coprocessor will
1044 be used nevertheless. (This behavior can be changed with the kernel
1045 command line option "no387", which comes handy if your coprocessor
1046 is broken. Try "man bootparam" or see the documentation of your boot
1047 loader (lilo or loadlin) about how to pass options to the kernel at
1048 boot time.) This means that it is a good idea to say Y here if you
1049 intend to use this kernel on different machines.
1051 More information about the internals of the Linux math coprocessor
1052 emulation can be found in <file:arch/x86/math-emu/README>.
1054 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1055 kernel, it won't hurt.
1058 bool "MTRR (Memory Type Range Register) support"
1060 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1061 the Memory Type Range Registers (MTRRs) may be used to control
1062 processor access to memory ranges. This is most useful if you have
1063 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1064 allows bus write transfers to be combined into a larger transfer
1065 before bursting over the PCI/AGP bus. This can increase performance
1066 of image write operations 2.5 times or more. Saying Y here creates a
1067 /proc/mtrr file which may be used to manipulate your processor's
1068 MTRRs. Typically the X server should use this.
1070 This code has a reasonably generic interface so that similar
1071 control registers on other processors can be easily supported
1074 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1075 Registers (ARRs) which provide a similar functionality to MTRRs. For
1076 these, the ARRs are used to emulate the MTRRs.
1077 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1078 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1079 write-combining. All of these processors are supported by this code
1080 and it makes sense to say Y here if you have one of them.
1082 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1083 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1084 can lead to all sorts of problems, so it's good to say Y here.
1086 You can safely say Y even if your machine doesn't have MTRRs, you'll
1087 just add about 9 KB to your kernel.
1089 See <file:Documentation/mtrr.txt> for more information.
1091 config MTRR_SANITIZER
1093 prompt "MTRR cleanup support"
1096 Convert MTRR layout from continuous to discrete, so some X driver
1097 could add WB entries.
1099 Say N here if you see bootup problems (boot crash, boot hang,
1100 spontaneous reboots).
1102 Could be disabled with disable_mtrr_cleanup. Also mtrr_chunk_size
1103 could be used to send largest mtrr entry size for continuous block
1104 to hold holes (aka. UC entries)
1108 config MTRR_SANITIZER_ENABLE_DEFAULT
1109 int "MTRR cleanup enable value (0-1)"
1112 depends on MTRR_SANITIZER
1114 Enable mtrr cleanup default value
1116 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1117 int "MTRR cleanup spare reg num (0-7)"
1120 depends on MTRR_SANITIZER
1122 mtrr cleanup spare entries default, it can be changed via
1127 prompt "x86 PAT support"
1130 Use PAT attributes to setup page level cache control.
1132 PATs are the modern equivalents of MTRRs and are much more
1133 flexible than MTRRs.
1135 Say N here if you see bootup problems (boot crash, boot hang,
1136 spontaneous reboots) or a non-working video driver.
1142 prompt "EFI runtime service support"
1145 This enables the kernel to use EFI runtime services that are
1146 available (such as the EFI variable services).
1148 This option is only useful on systems that have EFI firmware.
1149 In addition, you should use the latest ELILO loader available
1150 at <http://elilo.sourceforge.net> in order to take advantage
1151 of EFI runtime services. However, even with this option, the
1152 resultant kernel should continue to boot on existing non-EFI
1157 prompt "Enable kernel irq balancing"
1158 depends on X86_32 && SMP && X86_IO_APIC
1160 The default yes will allow the kernel to do irq load balancing.
1161 Saying no will keep the kernel from doing irq load balancing.
1165 prompt "Enable seccomp to safely compute untrusted bytecode"
1168 This kernel feature is useful for number crunching applications
1169 that may need to compute untrusted bytecode during their
1170 execution. By using pipes or other transports made available to
1171 the process as file descriptors supporting the read/write
1172 syscalls, it's possible to isolate those applications in
1173 their own address space using seccomp. Once seccomp is
1174 enabled via /proc/<pid>/seccomp, it cannot be disabled
1175 and the task is only allowed to execute a few safe syscalls
1176 defined by each seccomp mode.
1178 If unsure, say Y. Only embedded should say N here.
1180 config CC_STACKPROTECTOR
1181 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1182 depends on X86_64 && EXPERIMENTAL && BROKEN
1184 This option turns on the -fstack-protector GCC feature. This
1185 feature puts, at the beginning of critical functions, a canary
1186 value on the stack just before the return address, and validates
1187 the value just before actually returning. Stack based buffer
1188 overflows (that need to overwrite this return address) now also
1189 overwrite the canary, which gets detected and the attack is then
1190 neutralized via a kernel panic.
1192 This feature requires gcc version 4.2 or above, or a distribution
1193 gcc with the feature backported. Older versions are automatically
1194 detected and for those versions, this configuration option is ignored.
1196 config CC_STACKPROTECTOR_ALL
1197 bool "Use stack-protector for all functions"
1198 depends on CC_STACKPROTECTOR
1200 Normally, GCC only inserts the canary value protection for
1201 functions that use large-ish on-stack buffers. By enabling
1202 this option, GCC will be asked to do this for ALL functions.
1204 source kernel/Kconfig.hz
1207 bool "kexec system call"
1208 depends on X86_BIOS_REBOOT
1210 kexec is a system call that implements the ability to shutdown your
1211 current kernel, and to start another kernel. It is like a reboot
1212 but it is independent of the system firmware. And like a reboot
1213 you can start any kernel with it, not just Linux.
1215 The name comes from the similarity to the exec system call.
1217 It is an ongoing process to be certain the hardware in a machine
1218 is properly shutdown, so do not be surprised if this code does not
1219 initially work for you. It may help to enable device hotplugging
1220 support. As of this writing the exact hardware interface is
1221 strongly in flux, so no good recommendation can be made.
1224 bool "kernel crash dumps (EXPERIMENTAL)"
1225 depends on EXPERIMENTAL
1226 depends on X86_64 || (X86_32 && HIGHMEM)
1228 Generate crash dump after being started by kexec.
1229 This should be normally only set in special crash dump kernels
1230 which are loaded in the main kernel with kexec-tools into
1231 a specially reserved region and then later executed after
1232 a crash by kdump/kexec. The crash dump kernel must be compiled
1233 to a memory address not used by the main kernel or BIOS using
1234 PHYSICAL_START, or it must be built as a relocatable image
1235 (CONFIG_RELOCATABLE=y).
1236 For more details see Documentation/kdump/kdump.txt
1238 config PHYSICAL_START
1239 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1240 default "0x1000000" if X86_NUMAQ
1241 default "0x200000" if X86_64
1244 This gives the physical address where the kernel is loaded.
1246 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1247 bzImage will decompress itself to above physical address and
1248 run from there. Otherwise, bzImage will run from the address where
1249 it has been loaded by the boot loader and will ignore above physical
1252 In normal kdump cases one does not have to set/change this option
1253 as now bzImage can be compiled as a completely relocatable image
1254 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1255 address. This option is mainly useful for the folks who don't want
1256 to use a bzImage for capturing the crash dump and want to use a
1257 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1258 to be specifically compiled to run from a specific memory area
1259 (normally a reserved region) and this option comes handy.
1261 So if you are using bzImage for capturing the crash dump, leave
1262 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1263 Otherwise if you plan to use vmlinux for capturing the crash dump
1264 change this value to start of the reserved region (Typically 16MB
1265 0x1000000). In other words, it can be set based on the "X" value as
1266 specified in the "crashkernel=YM@XM" command line boot parameter
1267 passed to the panic-ed kernel. Typically this parameter is set as
1268 crashkernel=64M@16M. Please take a look at
1269 Documentation/kdump/kdump.txt for more details about crash dumps.
1271 Usage of bzImage for capturing the crash dump is recommended as
1272 one does not have to build two kernels. Same kernel can be used
1273 as production kernel and capture kernel. Above option should have
1274 gone away after relocatable bzImage support is introduced. But it
1275 is present because there are users out there who continue to use
1276 vmlinux for dump capture. This option should go away down the
1279 Don't change this unless you know what you are doing.
1282 bool "Build a relocatable kernel (EXPERIMENTAL)"
1283 depends on EXPERIMENTAL
1285 This builds a kernel image that retains relocation information
1286 so it can be loaded someplace besides the default 1MB.
1287 The relocations tend to make the kernel binary about 10% larger,
1288 but are discarded at runtime.
1290 One use is for the kexec on panic case where the recovery kernel
1291 must live at a different physical address than the primary
1294 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1295 it has been loaded at and the compile time physical address
1296 (CONFIG_PHYSICAL_START) is ignored.
1298 config PHYSICAL_ALIGN
1300 prompt "Alignment value to which kernel should be aligned" if X86_32
1301 default "0x100000" if X86_32
1302 default "0x200000" if X86_64
1303 range 0x2000 0x400000
1305 This value puts the alignment restrictions on physical address
1306 where kernel is loaded and run from. Kernel is compiled for an
1307 address which meets above alignment restriction.
1309 If bootloader loads the kernel at a non-aligned address and
1310 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1311 address aligned to above value and run from there.
1313 If bootloader loads the kernel at a non-aligned address and
1314 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1315 load address and decompress itself to the address it has been
1316 compiled for and run from there. The address for which kernel is
1317 compiled already meets above alignment restrictions. Hence the
1318 end result is that kernel runs from a physical address meeting
1319 above alignment restrictions.
1321 Don't change this unless you know what you are doing.
1324 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1325 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1327 Say Y here to experiment with turning CPUs off and on, and to
1328 enable suspend on SMP systems. CPUs can be controlled through
1329 /sys/devices/system/cpu.
1330 Say N if you want to disable CPU hotplug and don't need to
1335 prompt "Compat VDSO support"
1336 depends on X86_32 || IA32_EMULATION
1338 Map the 32-bit VDSO to the predictable old-style address too.
1340 Say N here if you are running a sufficiently recent glibc
1341 version (2.3.3 or later), to remove the high-mapped
1342 VDSO mapping and to exclusively use the randomized VDSO.
1348 config ARCH_ENABLE_MEMORY_HOTPLUG
1350 depends on X86_64 || (X86_32 && HIGHMEM)
1352 config HAVE_ARCH_EARLY_PFN_TO_NID
1356 menu "Power management options"
1357 depends on !X86_VOYAGER
1359 config ARCH_HIBERNATION_HEADER
1361 depends on X86_64 && HIBERNATION
1363 source "kernel/power/Kconfig"
1365 source "drivers/acpi/Kconfig"
1370 depends on APM || APM_MODULE
1373 tristate "APM (Advanced Power Management) BIOS support"
1374 depends on X86_32 && PM_SLEEP && !X86_VISWS
1376 APM is a BIOS specification for saving power using several different
1377 techniques. This is mostly useful for battery powered laptops with
1378 APM compliant BIOSes. If you say Y here, the system time will be
1379 reset after a RESUME operation, the /proc/apm device will provide
1380 battery status information, and user-space programs will receive
1381 notification of APM "events" (e.g. battery status change).
1383 If you select "Y" here, you can disable actual use of the APM
1384 BIOS by passing the "apm=off" option to the kernel at boot time.
1386 Note that the APM support is almost completely disabled for
1387 machines with more than one CPU.
1389 In order to use APM, you will need supporting software. For location
1390 and more information, read <file:Documentation/power/pm.txt> and the
1391 Battery Powered Linux mini-HOWTO, available from
1392 <http://www.tldp.org/docs.html#howto>.
1394 This driver does not spin down disk drives (see the hdparm(8)
1395 manpage ("man 8 hdparm") for that), and it doesn't turn off
1396 VESA-compliant "green" monitors.
1398 This driver does not support the TI 4000M TravelMate and the ACER
1399 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1400 desktop machines also don't have compliant BIOSes, and this driver
1401 may cause those machines to panic during the boot phase.
1403 Generally, if you don't have a battery in your machine, there isn't
1404 much point in using this driver and you should say N. If you get
1405 random kernel OOPSes or reboots that don't seem to be related to
1406 anything, try disabling/enabling this option (or disabling/enabling
1409 Some other things you should try when experiencing seemingly random,
1412 1) make sure that you have enough swap space and that it is
1414 2) pass the "no-hlt" option to the kernel
1415 3) switch on floating point emulation in the kernel and pass
1416 the "no387" option to the kernel
1417 4) pass the "floppy=nodma" option to the kernel
1418 5) pass the "mem=4M" option to the kernel (thereby disabling
1419 all but the first 4 MB of RAM)
1420 6) make sure that the CPU is not over clocked.
1421 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1422 8) disable the cache from your BIOS settings
1423 9) install a fan for the video card or exchange video RAM
1424 10) install a better fan for the CPU
1425 11) exchange RAM chips
1426 12) exchange the motherboard.
1428 To compile this driver as a module, choose M here: the
1429 module will be called apm.
1433 config APM_IGNORE_USER_SUSPEND
1434 bool "Ignore USER SUSPEND"
1436 This option will ignore USER SUSPEND requests. On machines with a
1437 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1438 series notebooks, it is necessary to say Y because of a BIOS bug.
1440 config APM_DO_ENABLE
1441 bool "Enable PM at boot time"
1443 Enable APM features at boot time. From page 36 of the APM BIOS
1444 specification: "When disabled, the APM BIOS does not automatically
1445 power manage devices, enter the Standby State, enter the Suspend
1446 State, or take power saving steps in response to CPU Idle calls."
1447 This driver will make CPU Idle calls when Linux is idle (unless this
1448 feature is turned off -- see "Do CPU IDLE calls", below). This
1449 should always save battery power, but more complicated APM features
1450 will be dependent on your BIOS implementation. You may need to turn
1451 this option off if your computer hangs at boot time when using APM
1452 support, or if it beeps continuously instead of suspending. Turn
1453 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1454 T400CDT. This is off by default since most machines do fine without
1458 bool "Make CPU Idle calls when idle"
1460 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1461 On some machines, this can activate improved power savings, such as
1462 a slowed CPU clock rate, when the machine is idle. These idle calls
1463 are made after the idle loop has run for some length of time (e.g.,
1464 333 mS). On some machines, this will cause a hang at boot time or
1465 whenever the CPU becomes idle. (On machines with more than one CPU,
1466 this option does nothing.)
1468 config APM_DISPLAY_BLANK
1469 bool "Enable console blanking using APM"
1471 Enable console blanking using the APM. Some laptops can use this to
1472 turn off the LCD backlight when the screen blanker of the Linux
1473 virtual console blanks the screen. Note that this is only used by
1474 the virtual console screen blanker, and won't turn off the backlight
1475 when using the X Window system. This also doesn't have anything to
1476 do with your VESA-compliant power-saving monitor. Further, this
1477 option doesn't work for all laptops -- it might not turn off your
1478 backlight at all, or it might print a lot of errors to the console,
1479 especially if you are using gpm.
1481 config APM_ALLOW_INTS
1482 bool "Allow interrupts during APM BIOS calls"
1484 Normally we disable external interrupts while we are making calls to
1485 the APM BIOS as a measure to lessen the effects of a badly behaving
1486 BIOS implementation. The BIOS should reenable interrupts if it
1487 needs to. Unfortunately, some BIOSes do not -- especially those in
1488 many of the newer IBM Thinkpads. If you experience hangs when you
1489 suspend, try setting this to Y. Otherwise, say N.
1491 config APM_REAL_MODE_POWER_OFF
1492 bool "Use real mode APM BIOS call to power off"
1494 Use real mode APM BIOS calls to switch off the computer. This is
1495 a work-around for a number of buggy BIOSes. Switch this option on if
1496 your computer crashes instead of powering off properly.
1500 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1502 source "drivers/cpuidle/Kconfig"
1507 menu "Bus options (PCI etc.)"
1510 bool "PCI support" if !X86_VISWS && !X86_VSMP
1511 depends on !X86_VOYAGER
1513 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1515 Find out whether you have a PCI motherboard. PCI is the name of a
1516 bus system, i.e. the way the CPU talks to the other stuff inside
1517 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1518 VESA. If you have PCI, say Y, otherwise N.
1521 prompt "PCI access mode"
1522 depends on X86_32 && PCI && !X86_VISWS
1525 On PCI systems, the BIOS can be used to detect the PCI devices and
1526 determine their configuration. However, some old PCI motherboards
1527 have BIOS bugs and may crash if this is done. Also, some embedded
1528 PCI-based systems don't have any BIOS at all. Linux can also try to
1529 detect the PCI hardware directly without using the BIOS.
1531 With this option, you can specify how Linux should detect the
1532 PCI devices. If you choose "BIOS", the BIOS will be used,
1533 if you choose "Direct", the BIOS won't be used, and if you
1534 choose "MMConfig", then PCI Express MMCONFIG will be used.
1535 If you choose "Any", the kernel will try MMCONFIG, then the
1536 direct access method and falls back to the BIOS if that doesn't
1537 work. If unsure, go with the default, which is "Any".
1542 config PCI_GOMMCONFIG
1559 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1561 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1564 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC) || X86_VISWS)
1568 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1572 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1579 bool "Support mmconfig PCI config space access"
1580 depends on X86_64 && PCI && ACPI
1583 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1584 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1586 DMA remapping (DMAR) devices support enables independent address
1587 translations for Direct Memory Access (DMA) from devices.
1588 These DMA remapping devices are reported via ACPI tables
1589 and include PCI device scope covered by these DMA
1594 prompt "Support for Graphics workaround"
1597 Current Graphics drivers tend to use physical address
1598 for DMA and avoid using DMA APIs. Setting this config
1599 option permits the IOMMU driver to set a unity map for
1600 all the OS-visible memory. Hence the driver can continue
1601 to use physical addresses for DMA.
1603 config DMAR_FLOPPY_WA
1607 Floppy disk drivers are know to bypass DMA API calls
1608 thereby failing to work when IOMMU is enabled. This
1609 workaround will setup a 1:1 mapping for the first
1610 16M to make floppy (an ISA device) work.
1612 source "drivers/pci/pcie/Kconfig"
1614 source "drivers/pci/Kconfig"
1616 # x86_64 have no ISA slots, but do have ISA-style DMA.
1624 depends on !(X86_VOYAGER || X86_VISWS)
1626 Find out whether you have ISA slots on your motherboard. ISA is the
1627 name of a bus system, i.e. the way the CPU talks to the other stuff
1628 inside your box. Other bus systems are PCI, EISA, MicroChannel
1629 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1630 newer boards don't support it. If you have ISA, say Y, otherwise N.
1636 The Extended Industry Standard Architecture (EISA) bus was
1637 developed as an open alternative to the IBM MicroChannel bus.
1639 The EISA bus provided some of the features of the IBM MicroChannel
1640 bus while maintaining backward compatibility with cards made for
1641 the older ISA bus. The EISA bus saw limited use between 1988 and
1642 1995 when it was made obsolete by the PCI bus.
1644 Say Y here if you are building a kernel for an EISA-based machine.
1648 source "drivers/eisa/Kconfig"
1651 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1652 default y if X86_VOYAGER
1654 MicroChannel Architecture is found in some IBM PS/2 machines and
1655 laptops. It is a bus system similar to PCI or ISA. See
1656 <file:Documentation/mca.txt> (and especially the web page given
1657 there) before attempting to build an MCA bus kernel.
1659 source "drivers/mca/Kconfig"
1662 tristate "NatSemi SCx200 support"
1663 depends on !X86_VOYAGER
1665 This provides basic support for National Semiconductor's
1666 (now AMD's) Geode processors. The driver probes for the
1667 PCI-IDs of several on-chip devices, so its a good dependency
1668 for other scx200_* drivers.
1670 If compiled as a module, the driver is named scx200.
1672 config SCx200HR_TIMER
1673 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1674 depends on SCx200 && GENERIC_TIME
1677 This driver provides a clocksource built upon the on-chip
1678 27MHz high-resolution timer. Its also a workaround for
1679 NSC Geode SC-1100's buggy TSC, which loses time when the
1680 processor goes idle (as is done by the scheduler). The
1681 other workaround is idle=poll boot option.
1683 config GEODE_MFGPT_TIMER
1685 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1686 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1688 This driver provides a clock event source based on the MFGPT
1689 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1690 MFGPTs have a better resolution and max interval than the
1691 generic PIT, and are suitable for use as high-res timers.
1694 bool "One Laptop Per Child support"
1697 Add support for detecting the unique features of the OLPC
1704 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1706 source "drivers/pcmcia/Kconfig"
1708 source "drivers/pci/hotplug/Kconfig"
1713 menu "Executable file formats / Emulations"
1715 source "fs/Kconfig.binfmt"
1717 config IA32_EMULATION
1718 bool "IA32 Emulation"
1720 select COMPAT_BINFMT_ELF
1722 Include code to run 32-bit programs under a 64-bit kernel. You should
1723 likely turn this on, unless you're 100% sure that you don't have any
1724 32-bit programs left.
1727 tristate "IA32 a.out support"
1728 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1730 Support old a.out binaries in the 32bit emulation.
1734 depends on IA32_EMULATION
1736 config COMPAT_FOR_U64_ALIGNMENT
1740 config SYSVIPC_COMPAT
1742 depends on X86_64 && COMPAT && SYSVIPC
1747 source "net/Kconfig"
1749 source "drivers/Kconfig"
1751 source "drivers/firmware/Kconfig"
1755 source "arch/x86/Kconfig.debug"
1757 source "security/Kconfig"
1759 source "crypto/Kconfig"
1761 source "arch/x86/kvm/Kconfig"
1763 source "lib/Kconfig"