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_SMP || (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_VOYAGER) || X86_64
187 config X86_BIOS_REBOOT
189 depends on !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.
233 config X86_FIND_SMP_CONFIG
235 depends on X86_MPPARSE || X86_VOYAGER
240 bool "Enable MPS table"
241 depends on X86_LOCAL_APIC
243 For old smp systems that do not have proper acpi support. Newer systems
244 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
250 depends on X86_LOCAL_APIC
254 prompt "Subarchitecture Type"
260 Choose this option if your computer is a standard PC or compatible.
266 Select this for an AMD Elan processor.
268 Do not use this option for K6/Athlon/Opteron processors!
270 If unsure, choose "PC-compatible" instead.
274 depends on X86_32 && (SMP || BROKEN) && !PCI
276 Voyager is an MCA-based 32-way capable SMP architecture proprietary
277 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
281 If you do not specifically know you have a Voyager based machine,
282 say N here, otherwise the kernel you build will not be bootable.
284 config X86_GENERICARCH
285 bool "Generic architecture"
288 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
289 subarchitectures. It is intended for a generic binary kernel.
290 if you select them all, kernel will probe it one by one. and will
296 bool "NUMAQ (IBM/Sequent)"
297 depends on SMP && X86_32 && PCI && X86_MPPARSE
300 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
301 NUMA multiquad box. This changes the way that processors are
302 bootstrapped, and uses Clustered Logical APIC addressing mode instead
303 of Flat Logical. You will need a new lynxer.elf file to flash your
304 firmware with - send email to <Martin.Bligh@us.ibm.com>.
307 bool "Summit/EXA (IBM x440)"
308 depends on X86_32 && SMP
310 This option is needed for IBM systems that use the Summit/EXA chipset.
311 In particular, it is needed for the x440.
314 bool "Support for Unisys ES7000 IA32 series"
315 depends on X86_32 && SMP
317 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
318 supposed to run on an IA32-based Unisys ES7000 system.
321 bool "Support for big SMP systems with more than 8 CPUs"
322 depends on X86_32 && SMP
324 This option is needed for the systems that have more than 8 CPUs
325 and if the system is not of any sub-arch type above.
330 bool "RDC R-321x SoC"
333 select X86_REBOOTFIXUPS
339 This option is needed for RDC R-321x system-on-chip, also known
341 If you don't have one of these chips, you should say N here.
344 bool "Support for ScaleMP vSMP"
346 depends on X86_64 && PCI
348 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
349 supposed to run on these EM64T-based machines. Only choose this option
350 if you have one of these machines.
355 bool "SGI 320/540 (Visual Workstation)"
356 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
358 The SGI Visual Workstation series is an IA32-based workstation
359 based on SGI systems chips with some legacy PC hardware attached.
361 Say Y here to create a kernel to run on the SGI 320 or 540.
363 A kernel compiled for the Visual Workstation will run on general
364 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
366 config SCHED_NO_NO_OMIT_FRAME_POINTER
368 prompt "Single-depth WCHAN output"
371 Calculate simpler /proc/<PID>/wchan values. If this option
372 is disabled then wchan values will recurse back to the
373 caller function. This provides more accurate wchan values,
374 at the expense of slightly more scheduling overhead.
376 If in doubt, say "Y".
378 menuconfig PARAVIRT_GUEST
379 bool "Paravirtualized guest support"
381 Say Y here to get to see options related to running Linux under
382 various hypervisors. This option alone does not add any kernel code.
384 If you say N, all options in this submenu will be skipped and disabled.
388 source "arch/x86/xen/Kconfig"
391 bool "VMI Guest support"
394 depends on !X86_VOYAGER
396 VMI provides a paravirtualized interface to the VMware ESX server
397 (it could be used by other hypervisors in theory too, but is not
398 at the moment), by linking the kernel to a GPL-ed ROM module
399 provided by the hypervisor.
402 bool "KVM paravirtualized clock"
404 select PARAVIRT_CLOCK
405 depends on !X86_VOYAGER
407 Turning on this option will allow you to run a paravirtualized clock
408 when running over the KVM hypervisor. Instead of relying on a PIT
409 (or probably other) emulation by the underlying device model, the host
410 provides the guest with timing infrastructure such as time of day, and
414 bool "KVM Guest support"
416 depends on !X86_VOYAGER
418 This option enables various optimizations for running under the KVM
421 source "arch/x86/lguest/Kconfig"
424 bool "Enable paravirtualization code"
425 depends on !X86_VOYAGER
427 This changes the kernel so it can modify itself when it is run
428 under a hypervisor, potentially improving performance significantly
429 over full virtualization. However, when run without a hypervisor
430 the kernel is theoretically slower and slightly larger.
432 config PARAVIRT_CLOCK
438 config PARAVIRT_DEBUG
439 bool "paravirt-ops debugging"
440 depends on PARAVIRT && DEBUG_KERNEL
442 Enable to debug paravirt_ops internals. Specifically, BUG if
443 a paravirt_op is missing when it is called.
450 This option adds a kernel parameter 'memtest', which allows memtest
452 memtest=0, mean disabled; -- default
453 memtest=1, mean do 1 test pattern;
455 memtest=4, mean do 4 test patterns.
456 If you are unsure how to answer this question, answer Y.
458 config X86_SUMMIT_NUMA
460 depends on X86_32 && NUMA && X86_GENERICARCH
462 config X86_CYCLONE_TIMER
464 depends on 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.
553 bool "AMD IOMMU support"
555 depends on X86_64 && PCI && ACPI
557 With this option you can enable support for AMD IOMMU hardware in
558 your system. An IOMMU is a hardware component which provides
559 remapping of DMA memory accesses from devices. With an AMD IOMMU you
560 can isolate the the DMA memory of different devices and protect the
561 system from misbehaving device drivers or hardware.
563 You can find out if your system has an AMD IOMMU if you look into
564 your BIOS for an option to enable it or if you have an IVRS ACPI
567 # need this always selected by IOMMU for the VIA workaround
571 Support for software bounce buffers used on x86-64 systems
572 which don't have a hardware IOMMU (e.g. the current generation
573 of Intel's x86-64 CPUs). Using this PCI devices which can only
574 access 32-bits of memory can be used on systems with more than
575 3 GB of memory. If unsure, say Y.
578 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
580 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
581 depends on X86_64 && SMP
584 Configure maximum number of CPUS and NUMA Nodes for this architecture.
595 int "Maximum number of CPUs (2-4096)"
598 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
601 This allows you to specify the maximum number of CPUs which this
602 kernel will support. The maximum supported value is 4096 and the
603 minimum value which makes sense is 2.
605 This is purely to save memory - each supported CPU adds
606 approximately eight kilobytes to the kernel image.
610 bool "SMT (Hyperthreading) scheduler support"
613 SMT scheduler support improves the CPU scheduler's decision making
614 when dealing with Intel Pentium 4 chips with HyperThreading at a
615 cost of slightly increased overhead in some places. If unsure say
620 prompt "Multi-core scheduler support"
623 Multi-core scheduler support improves the CPU scheduler's decision
624 making when dealing with multi-core CPU chips at a cost of slightly
625 increased overhead in some places. If unsure say N here.
627 source "kernel/Kconfig.preempt"
630 bool "Local APIC support on uniprocessors"
631 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
633 A local APIC (Advanced Programmable Interrupt Controller) is an
634 integrated interrupt controller in the CPU. If you have a single-CPU
635 system which has a processor with a local APIC, you can say Y here to
636 enable and use it. If you say Y here even though your machine doesn't
637 have a local APIC, then the kernel will still run with no slowdown at
638 all. The local APIC supports CPU-generated self-interrupts (timer,
639 performance counters), and the NMI watchdog which detects hard
643 bool "IO-APIC support on uniprocessors"
644 depends on X86_UP_APIC
646 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
647 SMP-capable replacement for PC-style interrupt controllers. Most
648 SMP systems and many recent uniprocessor systems have one.
650 If you have a single-CPU system with an IO-APIC, you can say Y here
651 to use it. If you say Y here even though your machine doesn't have
652 an IO-APIC, then the kernel will still run with no slowdown at all.
654 config X86_LOCAL_APIC
656 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
660 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
662 config X86_VISWS_APIC
664 depends on X86_32 && X86_VISWS
667 bool "Machine Check Exception"
668 depends on !X86_VOYAGER
670 Machine Check Exception support allows the processor to notify the
671 kernel if it detects a problem (e.g. overheating, component failure).
672 The action the kernel takes depends on the severity of the problem,
673 ranging from a warning message on the console, to halting the machine.
674 Your processor must be a Pentium or newer to support this - check the
675 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
676 have a design flaw which leads to false MCE events - hence MCE is
677 disabled on all P5 processors, unless explicitly enabled with "mce"
678 as a boot argument. Similarly, if MCE is built in and creates a
679 problem on some new non-standard machine, you can boot with "nomce"
680 to disable it. MCE support simply ignores non-MCE processors like
681 the 386 and 486, so nearly everyone can say Y here.
685 prompt "Intel MCE features"
686 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
688 Additional support for intel specific MCE features such as
693 prompt "AMD MCE features"
694 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
696 Additional support for AMD specific MCE features such as
697 the DRAM Error Threshold.
699 config X86_MCE_NONFATAL
700 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
701 depends on X86_32 && X86_MCE
703 Enabling this feature starts a timer that triggers every 5 seconds which
704 will look at the machine check registers to see if anything happened.
705 Non-fatal problems automatically get corrected (but still logged).
706 Disable this if you don't want to see these messages.
707 Seeing the messages this option prints out may be indicative of dying
708 or out-of-spec (ie, overclocked) hardware.
709 This option only does something on certain CPUs.
710 (AMD Athlon/Duron and Intel Pentium 4)
712 config X86_MCE_P4THERMAL
713 bool "check for P4 thermal throttling interrupt."
714 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
716 Enabling this feature will cause a message to be printed when the P4
717 enters thermal throttling.
720 bool "Enable VM86 support" if EMBEDDED
724 This option is required by programs like DOSEMU to run 16-bit legacy
725 code on X86 processors. It also may be needed by software like
726 XFree86 to initialize some video cards via BIOS. Disabling this
727 option saves about 6k.
730 tristate "Toshiba Laptop support"
733 This adds a driver to safely access the System Management Mode of
734 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
735 not work on models with a Phoenix BIOS. The System Management Mode
736 is used to set the BIOS and power saving options on Toshiba portables.
738 For information on utilities to make use of this driver see the
739 Toshiba Linux utilities web site at:
740 <http://www.buzzard.org.uk/toshiba/>.
742 Say Y if you intend to run this kernel on a Toshiba portable.
746 tristate "Dell laptop support"
748 This adds a driver to safely access the System Management Mode
749 of the CPU on the Dell Inspiron 8000. The System Management Mode
750 is used to read cpu temperature and cooling fan status and to
751 control the fans on the I8K portables.
753 This driver has been tested only on the Inspiron 8000 but it may
754 also work with other Dell laptops. You can force loading on other
755 models by passing the parameter `force=1' to the module. Use at
758 For information on utilities to make use of this driver see the
759 I8K Linux utilities web site at:
760 <http://people.debian.org/~dz/i8k/>
762 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
765 config X86_REBOOTFIXUPS
767 prompt "Enable X86 board specific fixups for reboot"
768 depends on X86_32 && X86
770 This enables chipset and/or board specific fixups to be done
771 in order to get reboot to work correctly. This is only needed on
772 some combinations of hardware and BIOS. The symptom, for which
773 this config is intended, is when reboot ends with a stalled/hung
776 Currently, the only fixup is for the Geode machines using
777 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
779 Say Y if you want to enable the fixup. Currently, it's safe to
780 enable this option even if you don't need it.
784 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
787 If you say Y here, you will be able to update the microcode on
788 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
789 Pentium III, Pentium 4, Xeon etc. You will obviously need the
790 actual microcode binary data itself which is not shipped with the
793 For latest news and information on obtaining all the required
794 ingredients for this driver, check:
795 <http://www.urbanmyth.org/microcode/>.
797 To compile this driver as a module, choose M here: the
798 module will be called microcode.
800 config MICROCODE_OLD_INTERFACE
805 tristate "/dev/cpu/*/msr - Model-specific register support"
807 This device gives privileged processes access to the x86
808 Model-Specific Registers (MSRs). It is a character device with
809 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
810 MSR accesses are directed to a specific CPU on multi-processor
814 tristate "/dev/cpu/*/cpuid - CPU information support"
816 This device gives processes access to the x86 CPUID instruction to
817 be executed on a specific processor. It is a character device
818 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
822 prompt "High Memory Support"
823 default HIGHMEM4G if !X86_NUMAQ
824 default HIGHMEM64G if X86_NUMAQ
829 depends on !X86_NUMAQ
831 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
832 However, the address space of 32-bit x86 processors is only 4
833 Gigabytes large. That means that, if you have a large amount of
834 physical memory, not all of it can be "permanently mapped" by the
835 kernel. The physical memory that's not permanently mapped is called
838 If you are compiling a kernel which will never run on a machine with
839 more than 1 Gigabyte total physical RAM, answer "off" here (default
840 choice and suitable for most users). This will result in a "3GB/1GB"
841 split: 3GB are mapped so that each process sees a 3GB virtual memory
842 space and the remaining part of the 4GB virtual memory space is used
843 by the kernel to permanently map as much physical memory as
846 If the machine has between 1 and 4 Gigabytes physical RAM, then
849 If more than 4 Gigabytes is used then answer "64GB" here. This
850 selection turns Intel PAE (Physical Address Extension) mode on.
851 PAE implements 3-level paging on IA32 processors. PAE is fully
852 supported by Linux, PAE mode is implemented on all recent Intel
853 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
854 then the kernel will not boot on CPUs that don't support PAE!
856 The actual amount of total physical memory will either be
857 auto detected or can be forced by using a kernel command line option
858 such as "mem=256M". (Try "man bootparam" or see the documentation of
859 your boot loader (lilo or loadlin) about how to pass options to the
860 kernel at boot time.)
862 If unsure, say "off".
866 depends on !X86_NUMAQ
868 Select this if you have a 32-bit processor and between 1 and 4
869 gigabytes of physical RAM.
873 depends on !M386 && !M486
876 Select this if you have a 32-bit processor and more than 4
877 gigabytes of physical RAM.
882 depends on EXPERIMENTAL
883 prompt "Memory split" if EMBEDDED
887 Select the desired split between kernel and user memory.
889 If the address range available to the kernel is less than the
890 physical memory installed, the remaining memory will be available
891 as "high memory". Accessing high memory is a little more costly
892 than low memory, as it needs to be mapped into the kernel first.
893 Note that increasing the kernel address space limits the range
894 available to user programs, making the address space there
895 tighter. Selecting anything other than the default 3G/1G split
896 will also likely make your kernel incompatible with binary-only
899 If you are not absolutely sure what you are doing, leave this
903 bool "3G/1G user/kernel split"
904 config VMSPLIT_3G_OPT
906 bool "3G/1G user/kernel split (for full 1G low memory)"
908 bool "2G/2G user/kernel split"
909 config VMSPLIT_2G_OPT
911 bool "2G/2G user/kernel split (for full 2G low memory)"
913 bool "1G/3G user/kernel split"
918 default 0xB0000000 if VMSPLIT_3G_OPT
919 default 0x80000000 if VMSPLIT_2G
920 default 0x78000000 if VMSPLIT_2G_OPT
921 default 0x40000000 if VMSPLIT_1G
927 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
931 prompt "PAE (Physical Address Extension) Support"
932 depends on X86_32 && !HIGHMEM4G
933 select RESOURCES_64BIT
935 PAE is required for NX support, and furthermore enables
936 larger swapspace support for non-overcommit purposes. It
937 has the cost of more pagetable lookup overhead, and also
938 consumes more pagetable space per process.
940 # Common NUMA Features
942 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
944 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
946 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
948 Enable NUMA (Non Uniform Memory Access) support.
949 The kernel will try to allocate memory used by a CPU on the
950 local memory controller of the CPU and add some more
951 NUMA awareness to the kernel.
953 For i386 this is currently highly experimental and should be only
954 used for kernel development. It might also cause boot failures.
955 For x86_64 this is recommended on all multiprocessor Opteron systems.
956 If the system is EM64T, you should say N unless your system is
959 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
960 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
964 prompt "Old style AMD Opteron NUMA detection"
965 depends on X86_64 && NUMA && PCI
967 Enable K8 NUMA node topology detection. You should say Y here if
968 you have a multi processor AMD K8 system. This uses an old
969 method to read the NUMA configuration directly from the builtin
970 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
971 instead, which also takes priority if both are compiled in.
973 config X86_64_ACPI_NUMA
975 prompt "ACPI NUMA detection"
976 depends on X86_64 && NUMA && ACPI && PCI
979 Enable ACPI SRAT based node topology detection.
981 # Some NUMA nodes have memory ranges that span
982 # other nodes. Even though a pfn is valid and
983 # between a node's start and end pfns, it may not
984 # reside on that node. See memmap_init_zone()
986 config NODES_SPAN_OTHER_NODES
988 depends on X86_64_ACPI_NUMA
991 bool "NUMA emulation"
992 depends on X86_64 && NUMA
994 Enable NUMA emulation. A flat machine will be split
995 into virtual nodes when booted with "numa=fake=N", where N is the
996 number of nodes. This is only useful for debugging.
1007 int "Maximum NUMA Nodes (as a power of 2)"
1009 default "6" if X86_64
1010 default "4" if X86_NUMAQ
1012 depends on NEED_MULTIPLE_NODES
1014 Specify the maximum number of NUMA Nodes available on the target
1015 system. Increases memory reserved to accomodate various tables.
1018 config HAVE_ARCH_BOOTMEM_NODE
1020 depends on X86_32 && NUMA
1022 config ARCH_HAVE_MEMORY_PRESENT
1024 depends on X86_32 && DISCONTIGMEM
1026 config NEED_NODE_MEMMAP_SIZE
1028 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1030 config HAVE_ARCH_ALLOC_REMAP
1032 depends on X86_32 && NUMA
1034 config ARCH_FLATMEM_ENABLE
1036 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
1038 config ARCH_DISCONTIGMEM_ENABLE
1040 depends on NUMA && X86_32
1042 config ARCH_DISCONTIGMEM_DEFAULT
1044 depends on NUMA && X86_32
1046 config ARCH_SPARSEMEM_DEFAULT
1050 config ARCH_SPARSEMEM_ENABLE
1052 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1053 select SPARSEMEM_STATIC if X86_32
1054 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1056 config ARCH_SELECT_MEMORY_MODEL
1058 depends on ARCH_SPARSEMEM_ENABLE
1060 config ARCH_MEMORY_PROBE
1062 depends on MEMORY_HOTPLUG
1067 bool "Allocate 3rd-level pagetables from highmem"
1068 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1070 The VM uses one page table entry for each page of physical memory.
1071 For systems with a lot of RAM, this can be wasteful of precious
1072 low memory. Setting this option will put user-space page table
1073 entries in high memory.
1075 config MATH_EMULATION
1077 prompt "Math emulation" if X86_32
1079 Linux can emulate a math coprocessor (used for floating point
1080 operations) if you don't have one. 486DX and Pentium processors have
1081 a math coprocessor built in, 486SX and 386 do not, unless you added
1082 a 487DX or 387, respectively. (The messages during boot time can
1083 give you some hints here ["man dmesg"].) Everyone needs either a
1084 coprocessor or this emulation.
1086 If you don't have a math coprocessor, you need to say Y here; if you
1087 say Y here even though you have a coprocessor, the coprocessor will
1088 be used nevertheless. (This behavior can be changed with the kernel
1089 command line option "no387", which comes handy if your coprocessor
1090 is broken. Try "man bootparam" or see the documentation of your boot
1091 loader (lilo or loadlin) about how to pass options to the kernel at
1092 boot time.) This means that it is a good idea to say Y here if you
1093 intend to use this kernel on different machines.
1095 More information about the internals of the Linux math coprocessor
1096 emulation can be found in <file:arch/x86/math-emu/README>.
1098 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1099 kernel, it won't hurt.
1102 bool "MTRR (Memory Type Range Register) support"
1104 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1105 the Memory Type Range Registers (MTRRs) may be used to control
1106 processor access to memory ranges. This is most useful if you have
1107 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1108 allows bus write transfers to be combined into a larger transfer
1109 before bursting over the PCI/AGP bus. This can increase performance
1110 of image write operations 2.5 times or more. Saying Y here creates a
1111 /proc/mtrr file which may be used to manipulate your processor's
1112 MTRRs. Typically the X server should use this.
1114 This code has a reasonably generic interface so that similar
1115 control registers on other processors can be easily supported
1118 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1119 Registers (ARRs) which provide a similar functionality to MTRRs. For
1120 these, the ARRs are used to emulate the MTRRs.
1121 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1122 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1123 write-combining. All of these processors are supported by this code
1124 and it makes sense to say Y here if you have one of them.
1126 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1127 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1128 can lead to all sorts of problems, so it's good to say Y here.
1130 You can safely say Y even if your machine doesn't have MTRRs, you'll
1131 just add about 9 KB to your kernel.
1133 See <file:Documentation/mtrr.txt> for more information.
1135 config MTRR_SANITIZER
1137 prompt "MTRR cleanup support"
1140 Convert MTRR layout from continuous to discrete, so some X driver
1141 could add WB entries.
1143 Say N here if you see bootup problems (boot crash, boot hang,
1144 spontaneous reboots).
1146 Could be disabled with disable_mtrr_cleanup. Also mtrr_chunk_size
1147 could be used to send largest mtrr entry size for continuous block
1148 to hold holes (aka. UC entries)
1152 config MTRR_SANITIZER_ENABLE_DEFAULT
1153 int "MTRR cleanup enable value (0-1)"
1156 depends on MTRR_SANITIZER
1158 Enable mtrr cleanup default value
1160 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1161 int "MTRR cleanup spare reg num (0-7)"
1164 depends on MTRR_SANITIZER
1166 mtrr cleanup spare entries default, it can be changed via
1171 prompt "x86 PAT support"
1174 Use PAT attributes to setup page level cache control.
1176 PATs are the modern equivalents of MTRRs and are much more
1177 flexible than MTRRs.
1179 Say N here if you see bootup problems (boot crash, boot hang,
1180 spontaneous reboots) or a non-working video driver.
1186 prompt "EFI runtime service support"
1189 This enables the kernel to use EFI runtime services that are
1190 available (such as the EFI variable services).
1192 This option is only useful on systems that have EFI firmware.
1193 In addition, you should use the latest ELILO loader available
1194 at <http://elilo.sourceforge.net> in order to take advantage
1195 of EFI runtime services. However, even with this option, the
1196 resultant kernel should continue to boot on existing non-EFI
1201 prompt "Enable kernel irq balancing"
1202 depends on X86_32 && SMP && X86_IO_APIC
1204 The default yes will allow the kernel to do irq load balancing.
1205 Saying no will keep the kernel from doing irq load balancing.
1209 prompt "Enable seccomp to safely compute untrusted bytecode"
1212 This kernel feature is useful for number crunching applications
1213 that may need to compute untrusted bytecode during their
1214 execution. By using pipes or other transports made available to
1215 the process as file descriptors supporting the read/write
1216 syscalls, it's possible to isolate those applications in
1217 their own address space using seccomp. Once seccomp is
1218 enabled via /proc/<pid>/seccomp, it cannot be disabled
1219 and the task is only allowed to execute a few safe syscalls
1220 defined by each seccomp mode.
1222 If unsure, say Y. Only embedded should say N here.
1224 config CC_STACKPROTECTOR
1225 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1226 depends on X86_64 && EXPERIMENTAL && BROKEN
1228 This option turns on the -fstack-protector GCC feature. This
1229 feature puts, at the beginning of critical functions, a canary
1230 value on the stack just before the return address, and validates
1231 the value just before actually returning. Stack based buffer
1232 overflows (that need to overwrite this return address) now also
1233 overwrite the canary, which gets detected and the attack is then
1234 neutralized via a kernel panic.
1236 This feature requires gcc version 4.2 or above, or a distribution
1237 gcc with the feature backported. Older versions are automatically
1238 detected and for those versions, this configuration option is ignored.
1240 config CC_STACKPROTECTOR_ALL
1241 bool "Use stack-protector for all functions"
1242 depends on CC_STACKPROTECTOR
1244 Normally, GCC only inserts the canary value protection for
1245 functions that use large-ish on-stack buffers. By enabling
1246 this option, GCC will be asked to do this for ALL functions.
1248 source kernel/Kconfig.hz
1251 bool "kexec system call"
1252 depends on X86_BIOS_REBOOT
1254 kexec is a system call that implements the ability to shutdown your
1255 current kernel, and to start another kernel. It is like a reboot
1256 but it is independent of the system firmware. And like a reboot
1257 you can start any kernel with it, not just Linux.
1259 The name comes from the similarity to the exec system call.
1261 It is an ongoing process to be certain the hardware in a machine
1262 is properly shutdown, so do not be surprised if this code does not
1263 initially work for you. It may help to enable device hotplugging
1264 support. As of this writing the exact hardware interface is
1265 strongly in flux, so no good recommendation can be made.
1268 bool "kernel crash dumps (EXPERIMENTAL)"
1269 depends on X86_64 || (X86_32 && HIGHMEM)
1271 Generate crash dump after being started by kexec.
1272 This should be normally only set in special crash dump kernels
1273 which are loaded in the main kernel with kexec-tools into
1274 a specially reserved region and then later executed after
1275 a crash by kdump/kexec. The crash dump kernel must be compiled
1276 to a memory address not used by the main kernel or BIOS using
1277 PHYSICAL_START, or it must be built as a relocatable image
1278 (CONFIG_RELOCATABLE=y).
1279 For more details see Documentation/kdump/kdump.txt
1281 config PHYSICAL_START
1282 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1283 default "0x1000000" if X86_NUMAQ
1284 default "0x200000" if X86_64
1287 This gives the physical address where the kernel is loaded.
1289 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1290 bzImage will decompress itself to above physical address and
1291 run from there. Otherwise, bzImage will run from the address where
1292 it has been loaded by the boot loader and will ignore above physical
1295 In normal kdump cases one does not have to set/change this option
1296 as now bzImage can be compiled as a completely relocatable image
1297 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1298 address. This option is mainly useful for the folks who don't want
1299 to use a bzImage for capturing the crash dump and want to use a
1300 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1301 to be specifically compiled to run from a specific memory area
1302 (normally a reserved region) and this option comes handy.
1304 So if you are using bzImage for capturing the crash dump, leave
1305 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1306 Otherwise if you plan to use vmlinux for capturing the crash dump
1307 change this value to start of the reserved region (Typically 16MB
1308 0x1000000). In other words, it can be set based on the "X" value as
1309 specified in the "crashkernel=YM@XM" command line boot parameter
1310 passed to the panic-ed kernel. Typically this parameter is set as
1311 crashkernel=64M@16M. Please take a look at
1312 Documentation/kdump/kdump.txt for more details about crash dumps.
1314 Usage of bzImage for capturing the crash dump is recommended as
1315 one does not have to build two kernels. Same kernel can be used
1316 as production kernel and capture kernel. Above option should have
1317 gone away after relocatable bzImage support is introduced. But it
1318 is present because there are users out there who continue to use
1319 vmlinux for dump capture. This option should go away down the
1322 Don't change this unless you know what you are doing.
1325 bool "Build a relocatable kernel (EXPERIMENTAL)"
1326 depends on EXPERIMENTAL
1328 This builds a kernel image that retains relocation information
1329 so it can be loaded someplace besides the default 1MB.
1330 The relocations tend to make the kernel binary about 10% larger,
1331 but are discarded at runtime.
1333 One use is for the kexec on panic case where the recovery kernel
1334 must live at a different physical address than the primary
1337 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1338 it has been loaded at and the compile time physical address
1339 (CONFIG_PHYSICAL_START) is ignored.
1341 config PHYSICAL_ALIGN
1343 prompt "Alignment value to which kernel should be aligned" if X86_32
1344 default "0x100000" if X86_32
1345 default "0x200000" if X86_64
1346 range 0x2000 0x400000
1348 This value puts the alignment restrictions on physical address
1349 where kernel is loaded and run from. Kernel is compiled for an
1350 address which meets above alignment restriction.
1352 If bootloader loads the kernel at a non-aligned address and
1353 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1354 address aligned to above value and run from there.
1356 If bootloader loads the kernel at a non-aligned address and
1357 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1358 load address and decompress itself to the address it has been
1359 compiled for and run from there. The address for which kernel is
1360 compiled already meets above alignment restrictions. Hence the
1361 end result is that kernel runs from a physical address meeting
1362 above alignment restrictions.
1364 Don't change this unless you know what you are doing.
1367 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1368 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1370 Say Y here to experiment with turning CPUs off and on, and to
1371 enable suspend on SMP systems. CPUs can be controlled through
1372 /sys/devices/system/cpu.
1373 Say N if you want to disable CPU hotplug and don't need to
1378 prompt "Compat VDSO support"
1379 depends on X86_32 || IA32_EMULATION
1381 Map the 32-bit VDSO to the predictable old-style address too.
1383 Say N here if you are running a sufficiently recent glibc
1384 version (2.3.3 or later), to remove the high-mapped
1385 VDSO mapping and to exclusively use the randomized VDSO.
1391 config ARCH_ENABLE_MEMORY_HOTPLUG
1393 depends on X86_64 || (X86_32 && HIGHMEM)
1395 config HAVE_ARCH_EARLY_PFN_TO_NID
1399 menu "Power management options"
1400 depends on !X86_VOYAGER
1402 config ARCH_HIBERNATION_HEADER
1404 depends on X86_64 && HIBERNATION
1406 source "kernel/power/Kconfig"
1408 source "drivers/acpi/Kconfig"
1413 depends on APM || APM_MODULE
1416 tristate "APM (Advanced Power Management) BIOS support"
1417 depends on X86_32 && PM_SLEEP
1419 APM is a BIOS specification for saving power using several different
1420 techniques. This is mostly useful for battery powered laptops with
1421 APM compliant BIOSes. If you say Y here, the system time will be
1422 reset after a RESUME operation, the /proc/apm device will provide
1423 battery status information, and user-space programs will receive
1424 notification of APM "events" (e.g. battery status change).
1426 If you select "Y" here, you can disable actual use of the APM
1427 BIOS by passing the "apm=off" option to the kernel at boot time.
1429 Note that the APM support is almost completely disabled for
1430 machines with more than one CPU.
1432 In order to use APM, you will need supporting software. For location
1433 and more information, read <file:Documentation/power/pm.txt> and the
1434 Battery Powered Linux mini-HOWTO, available from
1435 <http://www.tldp.org/docs.html#howto>.
1437 This driver does not spin down disk drives (see the hdparm(8)
1438 manpage ("man 8 hdparm") for that), and it doesn't turn off
1439 VESA-compliant "green" monitors.
1441 This driver does not support the TI 4000M TravelMate and the ACER
1442 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1443 desktop machines also don't have compliant BIOSes, and this driver
1444 may cause those machines to panic during the boot phase.
1446 Generally, if you don't have a battery in your machine, there isn't
1447 much point in using this driver and you should say N. If you get
1448 random kernel OOPSes or reboots that don't seem to be related to
1449 anything, try disabling/enabling this option (or disabling/enabling
1452 Some other things you should try when experiencing seemingly random,
1455 1) make sure that you have enough swap space and that it is
1457 2) pass the "no-hlt" option to the kernel
1458 3) switch on floating point emulation in the kernel and pass
1459 the "no387" option to the kernel
1460 4) pass the "floppy=nodma" option to the kernel
1461 5) pass the "mem=4M" option to the kernel (thereby disabling
1462 all but the first 4 MB of RAM)
1463 6) make sure that the CPU is not over clocked.
1464 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1465 8) disable the cache from your BIOS settings
1466 9) install a fan for the video card or exchange video RAM
1467 10) install a better fan for the CPU
1468 11) exchange RAM chips
1469 12) exchange the motherboard.
1471 To compile this driver as a module, choose M here: the
1472 module will be called apm.
1476 config APM_IGNORE_USER_SUSPEND
1477 bool "Ignore USER SUSPEND"
1479 This option will ignore USER SUSPEND requests. On machines with a
1480 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1481 series notebooks, it is necessary to say Y because of a BIOS bug.
1483 config APM_DO_ENABLE
1484 bool "Enable PM at boot time"
1486 Enable APM features at boot time. From page 36 of the APM BIOS
1487 specification: "When disabled, the APM BIOS does not automatically
1488 power manage devices, enter the Standby State, enter the Suspend
1489 State, or take power saving steps in response to CPU Idle calls."
1490 This driver will make CPU Idle calls when Linux is idle (unless this
1491 feature is turned off -- see "Do CPU IDLE calls", below). This
1492 should always save battery power, but more complicated APM features
1493 will be dependent on your BIOS implementation. You may need to turn
1494 this option off if your computer hangs at boot time when using APM
1495 support, or if it beeps continuously instead of suspending. Turn
1496 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1497 T400CDT. This is off by default since most machines do fine without
1501 bool "Make CPU Idle calls when idle"
1503 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1504 On some machines, this can activate improved power savings, such as
1505 a slowed CPU clock rate, when the machine is idle. These idle calls
1506 are made after the idle loop has run for some length of time (e.g.,
1507 333 mS). On some machines, this will cause a hang at boot time or
1508 whenever the CPU becomes idle. (On machines with more than one CPU,
1509 this option does nothing.)
1511 config APM_DISPLAY_BLANK
1512 bool "Enable console blanking using APM"
1514 Enable console blanking using the APM. Some laptops can use this to
1515 turn off the LCD backlight when the screen blanker of the Linux
1516 virtual console blanks the screen. Note that this is only used by
1517 the virtual console screen blanker, and won't turn off the backlight
1518 when using the X Window system. This also doesn't have anything to
1519 do with your VESA-compliant power-saving monitor. Further, this
1520 option doesn't work for all laptops -- it might not turn off your
1521 backlight at all, or it might print a lot of errors to the console,
1522 especially if you are using gpm.
1524 config APM_ALLOW_INTS
1525 bool "Allow interrupts during APM BIOS calls"
1527 Normally we disable external interrupts while we are making calls to
1528 the APM BIOS as a measure to lessen the effects of a badly behaving
1529 BIOS implementation. The BIOS should reenable interrupts if it
1530 needs to. Unfortunately, some BIOSes do not -- especially those in
1531 many of the newer IBM Thinkpads. If you experience hangs when you
1532 suspend, try setting this to Y. Otherwise, say N.
1534 config APM_REAL_MODE_POWER_OFF
1535 bool "Use real mode APM BIOS call to power off"
1537 Use real mode APM BIOS calls to switch off the computer. This is
1538 a work-around for a number of buggy BIOSes. Switch this option on if
1539 your computer crashes instead of powering off properly.
1543 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1545 source "drivers/cpuidle/Kconfig"
1550 menu "Bus options (PCI etc.)"
1555 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1557 Find out whether you have a PCI motherboard. PCI is the name of a
1558 bus system, i.e. the way the CPU talks to the other stuff inside
1559 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1560 VESA. If you have PCI, say Y, otherwise N.
1563 prompt "PCI access mode"
1564 depends on X86_32 && PCI
1567 On PCI systems, the BIOS can be used to detect the PCI devices and
1568 determine their configuration. However, some old PCI motherboards
1569 have BIOS bugs and may crash if this is done. Also, some embedded
1570 PCI-based systems don't have any BIOS at all. Linux can also try to
1571 detect the PCI hardware directly without using the BIOS.
1573 With this option, you can specify how Linux should detect the
1574 PCI devices. If you choose "BIOS", the BIOS will be used,
1575 if you choose "Direct", the BIOS won't be used, and if you
1576 choose "MMConfig", then PCI Express MMCONFIG will be used.
1577 If you choose "Any", the kernel will try MMCONFIG, then the
1578 direct access method and falls back to the BIOS if that doesn't
1579 work. If unsure, go with the default, which is "Any".
1584 config PCI_GOMMCONFIG
1601 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1603 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1606 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1610 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1614 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1621 bool "Support mmconfig PCI config space access"
1622 depends on X86_64 && PCI && ACPI
1625 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1626 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1628 DMA remapping (DMAR) devices support enables independent address
1629 translations for Direct Memory Access (DMA) from devices.
1630 These DMA remapping devices are reported via ACPI tables
1631 and include PCI device scope covered by these DMA
1636 prompt "Support for Graphics workaround"
1639 Current Graphics drivers tend to use physical address
1640 for DMA and avoid using DMA APIs. Setting this config
1641 option permits the IOMMU driver to set a unity map for
1642 all the OS-visible memory. Hence the driver can continue
1643 to use physical addresses for DMA.
1645 config DMAR_FLOPPY_WA
1649 Floppy disk drivers are know to bypass DMA API calls
1650 thereby failing to work when IOMMU is enabled. This
1651 workaround will setup a 1:1 mapping for the first
1652 16M to make floppy (an ISA device) work.
1654 source "drivers/pci/pcie/Kconfig"
1656 source "drivers/pci/Kconfig"
1658 # x86_64 have no ISA slots, but do have ISA-style DMA.
1666 depends on !X86_VOYAGER
1668 Find out whether you have ISA slots on your motherboard. ISA is the
1669 name of a bus system, i.e. the way the CPU talks to the other stuff
1670 inside your box. Other bus systems are PCI, EISA, MicroChannel
1671 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1672 newer boards don't support it. If you have ISA, say Y, otherwise N.
1678 The Extended Industry Standard Architecture (EISA) bus was
1679 developed as an open alternative to the IBM MicroChannel bus.
1681 The EISA bus provided some of the features of the IBM MicroChannel
1682 bus while maintaining backward compatibility with cards made for
1683 the older ISA bus. The EISA bus saw limited use between 1988 and
1684 1995 when it was made obsolete by the PCI bus.
1686 Say Y here if you are building a kernel for an EISA-based machine.
1690 source "drivers/eisa/Kconfig"
1693 bool "MCA support" if !X86_VOYAGER
1694 default y if X86_VOYAGER
1696 MicroChannel Architecture is found in some IBM PS/2 machines and
1697 laptops. It is a bus system similar to PCI or ISA. See
1698 <file:Documentation/mca.txt> (and especially the web page given
1699 there) before attempting to build an MCA bus kernel.
1701 source "drivers/mca/Kconfig"
1704 tristate "NatSemi SCx200 support"
1705 depends on !X86_VOYAGER
1707 This provides basic support for National Semiconductor's
1708 (now AMD's) Geode processors. The driver probes for the
1709 PCI-IDs of several on-chip devices, so its a good dependency
1710 for other scx200_* drivers.
1712 If compiled as a module, the driver is named scx200.
1714 config SCx200HR_TIMER
1715 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1716 depends on SCx200 && GENERIC_TIME
1719 This driver provides a clocksource built upon the on-chip
1720 27MHz high-resolution timer. Its also a workaround for
1721 NSC Geode SC-1100's buggy TSC, which loses time when the
1722 processor goes idle (as is done by the scheduler). The
1723 other workaround is idle=poll boot option.
1725 config GEODE_MFGPT_TIMER
1727 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1728 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1730 This driver provides a clock event source based on the MFGPT
1731 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1732 MFGPTs have a better resolution and max interval than the
1733 generic PIT, and are suitable for use as high-res timers.
1736 bool "One Laptop Per Child support"
1739 Add support for detecting the unique features of the OLPC
1746 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1748 source "drivers/pcmcia/Kconfig"
1750 source "drivers/pci/hotplug/Kconfig"
1755 menu "Executable file formats / Emulations"
1757 source "fs/Kconfig.binfmt"
1759 config IA32_EMULATION
1760 bool "IA32 Emulation"
1762 select COMPAT_BINFMT_ELF
1764 Include code to run 32-bit programs under a 64-bit kernel. You should
1765 likely turn this on, unless you're 100% sure that you don't have any
1766 32-bit programs left.
1769 tristate "IA32 a.out support"
1770 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1772 Support old a.out binaries in the 32bit emulation.
1776 depends on IA32_EMULATION
1778 config COMPAT_FOR_U64_ALIGNMENT
1782 config SYSVIPC_COMPAT
1784 depends on X86_64 && COMPAT && SYSVIPC
1789 source "net/Kconfig"
1791 source "drivers/Kconfig"
1793 source "drivers/firmware/Kconfig"
1797 source "arch/x86/Kconfig.debug"
1799 source "security/Kconfig"
1801 source "crypto/Kconfig"
1803 source "arch/x86/kvm/Kconfig"
1805 source "lib/Kconfig"
projects / linux-2.6 / blob