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_DYNAMIC_FTRACE
28 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
29 select HAVE_ARCH_KGDB if !X86_VOYAGER
33 default "arch/x86/configs/i386_defconfig" if X86_32
34 default "arch/x86/configs/x86_64_defconfig" if X86_64
37 config GENERIC_LOCKBREAK
43 config GENERIC_CMOS_UPDATE
46 config CLOCKSOURCE_WATCHDOG
49 config GENERIC_CLOCKEVENTS
52 config GENERIC_CLOCKEVENTS_BROADCAST
54 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
56 config LOCKDEP_SUPPORT
59 config STACKTRACE_SUPPORT
62 config HAVE_LATENCYTOP_SUPPORT
65 config FAST_CMPXCHG_LOCAL
78 config GENERIC_ISA_DMA
88 config GENERIC_HWEIGHT
94 config ARCH_MAY_HAVE_PC_FDC
97 config RWSEM_GENERIC_SPINLOCK
100 config RWSEM_XCHGADD_ALGORITHM
103 config ARCH_HAS_ILOG2_U32
106 config ARCH_HAS_ILOG2_U64
109 config ARCH_HAS_CPU_IDLE_WAIT
112 config GENERIC_CALIBRATE_DELAY
115 config GENERIC_TIME_VSYSCALL
119 config ARCH_HAS_CPU_RELAX
122 config ARCH_HAS_CACHE_LINE_SIZE
125 config HAVE_SETUP_PER_CPU_AREA
126 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
128 config HAVE_CPUMASK_OF_CPU_MAP
131 config ARCH_HIBERNATION_POSSIBLE
133 depends on !SMP || !X86_VOYAGER
135 config ARCH_SUSPEND_POSSIBLE
137 depends on !X86_VOYAGER
143 config ARCH_POPULATES_NODE_MAP
150 config ARCH_SUPPORTS_AOUT
153 config ARCH_SUPPORTS_OPTIMIZED_INLINING
156 # Use the generic interrupt handling code in kernel/irq/:
157 config GENERIC_HARDIRQS
161 config GENERIC_IRQ_PROBE
165 config GENERIC_PENDING_IRQ
167 depends on GENERIC_HARDIRQS && SMP
172 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
177 depends on X86_32 && SMP
181 depends on X86_64 && SMP
186 depends on (X86_32 && !X86_VOYAGER) || X86_64
189 config X86_BIOS_REBOOT
191 depends on !X86_VOYAGER
194 config X86_TRAMPOLINE
196 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
201 source "init/Kconfig"
203 menu "Processor type and features"
205 source "kernel/time/Kconfig"
208 bool "Symmetric multi-processing support"
210 This enables support for systems with more than one CPU. If you have
211 a system with only one CPU, like most personal computers, say N. If
212 you have a system with more than one CPU, say Y.
214 If you say N here, the kernel will run on single and multiprocessor
215 machines, but will use only one CPU of a multiprocessor machine. If
216 you say Y here, the kernel will run on many, but not all,
217 singleprocessor machines. On a singleprocessor machine, the kernel
218 will run faster if you say N here.
220 Note that if you say Y here and choose architecture "586" or
221 "Pentium" under "Processor family", the kernel will not work on 486
222 architectures. Similarly, multiprocessor kernels for the "PPro"
223 architecture may not work on all Pentium based boards.
225 People using multiprocessor machines who say Y here should also say
226 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
227 Management" code will be disabled if you say Y here.
229 See also <file:Documentation/i386/IO-APIC.txt>,
230 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
231 <http://www.tldp.org/docs.html#howto>.
233 If you don't know what to do here, say N.
235 config X86_FIND_SMP_CONFIG
237 depends on X86_MPPARSE || X86_VOYAGER
242 bool "Enable MPS table"
243 depends on X86_LOCAL_APIC
245 For old smp systems that do not have proper acpi support. Newer systems
246 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
252 depends on X86_LOCAL_APIC
256 prompt "Subarchitecture Type"
262 Choose this option if your computer is a standard PC or compatible.
268 Select this for an AMD Elan processor.
270 Do not use this option for K6/Athlon/Opteron processors!
272 If unsure, choose "PC-compatible" instead.
276 depends on X86_32 && (SMP || BROKEN) && !PCI
278 Voyager is an MCA-based 32-way capable SMP architecture proprietary
279 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
283 If you do not specifically know you have a Voyager based machine,
284 say N here, otherwise the kernel you build will not be bootable.
286 config X86_GENERICARCH
287 bool "Generic architecture"
290 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
291 subarchitectures. It is intended for a generic binary kernel.
292 if you select them all, kernel will probe it one by one. and will
298 bool "NUMAQ (IBM/Sequent)"
299 depends on SMP && X86_32 && PCI && X86_MPPARSE
302 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
303 NUMA multiquad box. This changes the way that processors are
304 bootstrapped, and uses Clustered Logical APIC addressing mode instead
305 of Flat Logical. You will need a new lynxer.elf file to flash your
306 firmware with - send email to <Martin.Bligh@us.ibm.com>.
309 bool "Summit/EXA (IBM x440)"
310 depends on X86_32 && SMP
312 This option is needed for IBM systems that use the Summit/EXA chipset.
313 In particular, it is needed for the x440.
316 bool "Support for Unisys ES7000 IA32 series"
317 depends on X86_32 && SMP
319 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
320 supposed to run on an IA32-based Unisys ES7000 system.
323 bool "Support for big SMP systems with more than 8 CPUs"
324 depends on X86_32 && SMP
326 This option is needed for the systems that have more than 8 CPUs
327 and if the system is not of any sub-arch type above.
332 bool "RDC R-321x SoC"
335 select X86_REBOOTFIXUPS
341 This option is needed for RDC R-321x system-on-chip, also known
343 If you don't have one of these chips, you should say N here.
346 bool "Support for ScaleMP vSMP"
348 depends on X86_64 && PCI
350 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
351 supposed to run on these EM64T-based machines. Only choose this option
352 if you have one of these machines.
357 bool "SGI 320/540 (Visual Workstation)"
358 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
360 The SGI Visual Workstation series is an IA32-based workstation
361 based on SGI systems chips with some legacy PC hardware attached.
363 Say Y here to create a kernel to run on the SGI 320 or 540.
365 A kernel compiled for the Visual Workstation will run on general
366 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
368 config SCHED_NO_NO_OMIT_FRAME_POINTER
370 prompt "Single-depth WCHAN output"
373 Calculate simpler /proc/<PID>/wchan values. If this option
374 is disabled then wchan values will recurse back to the
375 caller function. This provides more accurate wchan values,
376 at the expense of slightly more scheduling overhead.
378 If in doubt, say "Y".
380 menuconfig PARAVIRT_GUEST
381 bool "Paravirtualized guest support"
383 Say Y here to get to see options related to running Linux under
384 various hypervisors. This option alone does not add any kernel code.
386 If you say N, all options in this submenu will be skipped and disabled.
390 source "arch/x86/xen/Kconfig"
393 bool "VMI Guest support"
396 depends on !X86_VOYAGER
398 VMI provides a paravirtualized interface to the VMware ESX server
399 (it could be used by other hypervisors in theory too, but is not
400 at the moment), by linking the kernel to a GPL-ed ROM module
401 provided by the hypervisor.
404 bool "KVM paravirtualized clock"
406 select PARAVIRT_CLOCK
407 depends on !X86_VOYAGER
409 Turning on this option will allow you to run a paravirtualized clock
410 when running over the KVM hypervisor. Instead of relying on a PIT
411 (or probably other) emulation by the underlying device model, the host
412 provides the guest with timing infrastructure such as time of day, and
416 bool "KVM Guest support"
418 depends on !X86_VOYAGER
420 This option enables various optimizations for running under the KVM
423 source "arch/x86/lguest/Kconfig"
426 bool "Enable paravirtualization code"
427 depends on !X86_VOYAGER
429 This changes the kernel so it can modify itself when it is run
430 under a hypervisor, potentially improving performance significantly
431 over full virtualization. However, when run without a hypervisor
432 the kernel is theoretically slower and slightly larger.
434 config PARAVIRT_CLOCK
440 config PARAVIRT_DEBUG
441 bool "paravirt-ops debugging"
442 depends on PARAVIRT && DEBUG_KERNEL
444 Enable to debug paravirt_ops internals. Specifically, BUG if
445 a paravirt_op is missing when it is called.
452 This option adds a kernel parameter 'memtest', which allows memtest
454 memtest=0, mean disabled; -- default
455 memtest=1, mean do 1 test pattern;
457 memtest=4, mean do 4 test patterns.
458 If you are unsure how to answer this question, answer Y.
460 config X86_SUMMIT_NUMA
462 depends on X86_32 && NUMA && X86_GENERICARCH
464 config X86_CYCLONE_TIMER
466 depends on X86_GENERICARCH
468 config ES7000_CLUSTERED_APIC
470 depends on SMP && X86_ES7000 && MPENTIUMIII
472 source "arch/x86/Kconfig.cpu"
476 prompt "HPET Timer Support" if X86_32
478 Use the IA-PC HPET (High Precision Event Timer) to manage
479 time in preference to the PIT and RTC, if a HPET is
481 HPET is the next generation timer replacing legacy 8254s.
482 The HPET provides a stable time base on SMP
483 systems, unlike the TSC, but it is more expensive to access,
484 as it is off-chip. You can find the HPET spec at
485 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
487 You can safely choose Y here. However, HPET will only be
488 activated if the platform and the BIOS support this feature.
489 Otherwise the 8254 will be used for timing services.
491 Choose N to continue using the legacy 8254 timer.
493 config HPET_EMULATE_RTC
495 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
497 # Mark as embedded because too many people got it wrong.
498 # The code disables itself when not needed.
501 bool "Enable DMI scanning" if EMBEDDED
503 Enabled scanning of DMI to identify machine quirks. Say Y
504 here unless you have verified that your setup is not
505 affected by entries in the DMI blacklist. Required by PNP
509 bool "GART IOMMU support" if EMBEDDED
513 depends on X86_64 && PCI
515 Support for full DMA access of devices with 32bit memory access only
516 on systems with more than 3GB. This is usually needed for USB,
517 sound, many IDE/SATA chipsets and some other devices.
518 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
519 based hardware IOMMU and a software bounce buffer based IOMMU used
520 on Intel systems and as fallback.
521 The code is only active when needed (enough memory and limited
522 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
526 bool "IBM Calgary IOMMU support"
528 depends on X86_64 && PCI && EXPERIMENTAL
530 Support for hardware IOMMUs in IBM's xSeries x366 and x460
531 systems. Needed to run systems with more than 3GB of memory
532 properly with 32-bit PCI devices that do not support DAC
533 (Double Address Cycle). Calgary also supports bus level
534 isolation, where all DMAs pass through the IOMMU. This
535 prevents them from going anywhere except their intended
536 destination. This catches hard-to-find kernel bugs and
537 mis-behaving drivers and devices that do not use the DMA-API
538 properly to set up their DMA buffers. The IOMMU can be
539 turned off at boot time with the iommu=off parameter.
540 Normally the kernel will make the right choice by itself.
543 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
545 prompt "Should Calgary be enabled by default?"
546 depends on CALGARY_IOMMU
548 Should Calgary be enabled by default? if you choose 'y', Calgary
549 will be used (if it exists). If you choose 'n', Calgary will not be
550 used even if it exists. If you choose 'n' and would like to use
551 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
555 bool "AMD IOMMU support"
557 depends on X86_64 && PCI && ACPI
559 With this option you can enable support for AMD IOMMU hardware in
560 your system. An IOMMU is a hardware component which provides
561 remapping of DMA memory accesses from devices. With an AMD IOMMU you
562 can isolate the the DMA memory of different devices and protect the
563 system from misbehaving device drivers or hardware.
565 You can find out if your system has an AMD IOMMU if you look into
566 your BIOS for an option to enable it or if you have an IVRS ACPI
569 # need this always selected by IOMMU for the VIA workaround
573 Support for software bounce buffers used on x86-64 systems
574 which don't have a hardware IOMMU (e.g. the current generation
575 of Intel's x86-64 CPUs). Using this PCI devices which can only
576 access 32-bits of memory can be used on systems with more than
577 3 GB of memory. If unsure, say Y.
580 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
582 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
583 depends on X86_64 && SMP
586 Configure maximum number of CPUS and NUMA Nodes for this architecture.
597 int "Maximum number of CPUs (2-4096)"
600 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
603 This allows you to specify the maximum number of CPUs which this
604 kernel will support. The maximum supported value is 4096 and the
605 minimum value which makes sense is 2.
607 This is purely to save memory - each supported CPU adds
608 approximately eight kilobytes to the kernel image.
612 bool "SMT (Hyperthreading) scheduler support"
615 SMT scheduler support improves the CPU scheduler's decision making
616 when dealing with Intel Pentium 4 chips with HyperThreading at a
617 cost of slightly increased overhead in some places. If unsure say
622 prompt "Multi-core scheduler support"
625 Multi-core scheduler support improves the CPU scheduler's decision
626 making when dealing with multi-core CPU chips at a cost of slightly
627 increased overhead in some places. If unsure say N here.
629 source "kernel/Kconfig.preempt"
632 bool "Local APIC support on uniprocessors"
633 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
635 A local APIC (Advanced Programmable Interrupt Controller) is an
636 integrated interrupt controller in the CPU. If you have a single-CPU
637 system which has a processor with a local APIC, you can say Y here to
638 enable and use it. If you say Y here even though your machine doesn't
639 have a local APIC, then the kernel will still run with no slowdown at
640 all. The local APIC supports CPU-generated self-interrupts (timer,
641 performance counters), and the NMI watchdog which detects hard
645 bool "IO-APIC support on uniprocessors"
646 depends on X86_UP_APIC
648 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
649 SMP-capable replacement for PC-style interrupt controllers. Most
650 SMP systems and many recent uniprocessor systems have one.
652 If you have a single-CPU system with an IO-APIC, you can say Y here
653 to use it. If you say Y here even though your machine doesn't have
654 an IO-APIC, then the kernel will still run with no slowdown at all.
656 config X86_LOCAL_APIC
658 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
662 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
664 config X86_VISWS_APIC
666 depends on X86_32 && X86_VISWS
669 bool "Machine Check Exception"
670 depends on !X86_VOYAGER
672 Machine Check Exception support allows the processor to notify the
673 kernel if it detects a problem (e.g. overheating, component failure).
674 The action the kernel takes depends on the severity of the problem,
675 ranging from a warning message on the console, to halting the machine.
676 Your processor must be a Pentium or newer to support this - check the
677 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
678 have a design flaw which leads to false MCE events - hence MCE is
679 disabled on all P5 processors, unless explicitly enabled with "mce"
680 as a boot argument. Similarly, if MCE is built in and creates a
681 problem on some new non-standard machine, you can boot with "nomce"
682 to disable it. MCE support simply ignores non-MCE processors like
683 the 386 and 486, so nearly everyone can say Y here.
687 prompt "Intel MCE features"
688 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
690 Additional support for intel specific MCE features such as
695 prompt "AMD MCE features"
696 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
698 Additional support for AMD specific MCE features such as
699 the DRAM Error Threshold.
701 config X86_MCE_NONFATAL
702 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
703 depends on X86_32 && X86_MCE
705 Enabling this feature starts a timer that triggers every 5 seconds which
706 will look at the machine check registers to see if anything happened.
707 Non-fatal problems automatically get corrected (but still logged).
708 Disable this if you don't want to see these messages.
709 Seeing the messages this option prints out may be indicative of dying
710 or out-of-spec (ie, overclocked) hardware.
711 This option only does something on certain CPUs.
712 (AMD Athlon/Duron and Intel Pentium 4)
714 config X86_MCE_P4THERMAL
715 bool "check for P4 thermal throttling interrupt."
716 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
718 Enabling this feature will cause a message to be printed when the P4
719 enters thermal throttling.
722 bool "Enable VM86 support" if EMBEDDED
726 This option is required by programs like DOSEMU to run 16-bit legacy
727 code on X86 processors. It also may be needed by software like
728 XFree86 to initialize some video cards via BIOS. Disabling this
729 option saves about 6k.
732 tristate "Toshiba Laptop support"
735 This adds a driver to safely access the System Management Mode of
736 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
737 not work on models with a Phoenix BIOS. The System Management Mode
738 is used to set the BIOS and power saving options on Toshiba portables.
740 For information on utilities to make use of this driver see the
741 Toshiba Linux utilities web site at:
742 <http://www.buzzard.org.uk/toshiba/>.
744 Say Y if you intend to run this kernel on a Toshiba portable.
748 tristate "Dell laptop support"
750 This adds a driver to safely access the System Management Mode
751 of the CPU on the Dell Inspiron 8000. The System Management Mode
752 is used to read cpu temperature and cooling fan status and to
753 control the fans on the I8K portables.
755 This driver has been tested only on the Inspiron 8000 but it may
756 also work with other Dell laptops. You can force loading on other
757 models by passing the parameter `force=1' to the module. Use at
760 For information on utilities to make use of this driver see the
761 I8K Linux utilities web site at:
762 <http://people.debian.org/~dz/i8k/>
764 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
767 config X86_REBOOTFIXUPS
769 prompt "Enable X86 board specific fixups for reboot"
770 depends on X86_32 && X86
772 This enables chipset and/or board specific fixups to be done
773 in order to get reboot to work correctly. This is only needed on
774 some combinations of hardware and BIOS. The symptom, for which
775 this config is intended, is when reboot ends with a stalled/hung
778 Currently, the only fixup is for the Geode machines using
779 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
781 Say Y if you want to enable the fixup. Currently, it's safe to
782 enable this option even if you don't need it.
786 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
789 If you say Y here, you will be able to update the microcode on
790 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
791 Pentium III, Pentium 4, Xeon etc. You will obviously need the
792 actual microcode binary data itself which is not shipped with the
795 For latest news and information on obtaining all the required
796 ingredients for this driver, check:
797 <http://www.urbanmyth.org/microcode/>.
799 To compile this driver as a module, choose M here: the
800 module will be called microcode.
802 config MICROCODE_OLD_INTERFACE
807 tristate "/dev/cpu/*/msr - Model-specific register support"
809 This device gives privileged processes access to the x86
810 Model-Specific Registers (MSRs). It is a character device with
811 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
812 MSR accesses are directed to a specific CPU on multi-processor
816 tristate "/dev/cpu/*/cpuid - CPU information support"
818 This device gives processes access to the x86 CPUID instruction to
819 be executed on a specific processor. It is a character device
820 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
824 prompt "High Memory Support"
825 default HIGHMEM4G if !X86_NUMAQ
826 default HIGHMEM64G if X86_NUMAQ
831 depends on !X86_NUMAQ
833 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
834 However, the address space of 32-bit x86 processors is only 4
835 Gigabytes large. That means that, if you have a large amount of
836 physical memory, not all of it can be "permanently mapped" by the
837 kernel. The physical memory that's not permanently mapped is called
840 If you are compiling a kernel which will never run on a machine with
841 more than 1 Gigabyte total physical RAM, answer "off" here (default
842 choice and suitable for most users). This will result in a "3GB/1GB"
843 split: 3GB are mapped so that each process sees a 3GB virtual memory
844 space and the remaining part of the 4GB virtual memory space is used
845 by the kernel to permanently map as much physical memory as
848 If the machine has between 1 and 4 Gigabytes physical RAM, then
851 If more than 4 Gigabytes is used then answer "64GB" here. This
852 selection turns Intel PAE (Physical Address Extension) mode on.
853 PAE implements 3-level paging on IA32 processors. PAE is fully
854 supported by Linux, PAE mode is implemented on all recent Intel
855 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
856 then the kernel will not boot on CPUs that don't support PAE!
858 The actual amount of total physical memory will either be
859 auto detected or can be forced by using a kernel command line option
860 such as "mem=256M". (Try "man bootparam" or see the documentation of
861 your boot loader (lilo or loadlin) about how to pass options to the
862 kernel at boot time.)
864 If unsure, say "off".
868 depends on !X86_NUMAQ
870 Select this if you have a 32-bit processor and between 1 and 4
871 gigabytes of physical RAM.
875 depends on !M386 && !M486
878 Select this if you have a 32-bit processor and more than 4
879 gigabytes of physical RAM.
884 depends on EXPERIMENTAL
885 prompt "Memory split" if EMBEDDED
889 Select the desired split between kernel and user memory.
891 If the address range available to the kernel is less than the
892 physical memory installed, the remaining memory will be available
893 as "high memory". Accessing high memory is a little more costly
894 than low memory, as it needs to be mapped into the kernel first.
895 Note that increasing the kernel address space limits the range
896 available to user programs, making the address space there
897 tighter. Selecting anything other than the default 3G/1G split
898 will also likely make your kernel incompatible with binary-only
901 If you are not absolutely sure what you are doing, leave this
905 bool "3G/1G user/kernel split"
906 config VMSPLIT_3G_OPT
908 bool "3G/1G user/kernel split (for full 1G low memory)"
910 bool "2G/2G user/kernel split"
911 config VMSPLIT_2G_OPT
913 bool "2G/2G user/kernel split (for full 2G low memory)"
915 bool "1G/3G user/kernel split"
920 default 0xB0000000 if VMSPLIT_3G_OPT
921 default 0x80000000 if VMSPLIT_2G
922 default 0x78000000 if VMSPLIT_2G_OPT
923 default 0x40000000 if VMSPLIT_1G
929 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
933 prompt "PAE (Physical Address Extension) Support"
934 depends on X86_32 && !HIGHMEM4G
935 select RESOURCES_64BIT
937 PAE is required for NX support, and furthermore enables
938 larger swapspace support for non-overcommit purposes. It
939 has the cost of more pagetable lookup overhead, and also
940 consumes more pagetable space per process.
942 # Common NUMA Features
944 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
946 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
948 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
950 Enable NUMA (Non Uniform Memory Access) support.
951 The kernel will try to allocate memory used by a CPU on the
952 local memory controller of the CPU and add some more
953 NUMA awareness to the kernel.
955 For i386 this is currently highly experimental and should be only
956 used for kernel development. It might also cause boot failures.
957 For x86_64 this is recommended on all multiprocessor Opteron systems.
958 If the system is EM64T, you should say N unless your system is
961 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
962 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
966 prompt "Old style AMD Opteron NUMA detection"
967 depends on X86_64 && NUMA && PCI
969 Enable K8 NUMA node topology detection. You should say Y here if
970 you have a multi processor AMD K8 system. This uses an old
971 method to read the NUMA configuration directly from the builtin
972 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
973 instead, which also takes priority if both are compiled in.
975 config X86_64_ACPI_NUMA
977 prompt "ACPI NUMA detection"
978 depends on X86_64 && NUMA && ACPI && PCI
981 Enable ACPI SRAT based node topology detection.
983 # Some NUMA nodes have memory ranges that span
984 # other nodes. Even though a pfn is valid and
985 # between a node's start and end pfns, it may not
986 # reside on that node. See memmap_init_zone()
988 config NODES_SPAN_OTHER_NODES
990 depends on X86_64_ACPI_NUMA
993 bool "NUMA emulation"
994 depends on X86_64 && NUMA
996 Enable NUMA emulation. A flat machine will be split
997 into virtual nodes when booted with "numa=fake=N", where N is the
998 number of nodes. This is only useful for debugging.
1009 int "Maximum NUMA Nodes (as a power of 2)"
1011 default "6" if X86_64
1012 default "4" if X86_NUMAQ
1014 depends on NEED_MULTIPLE_NODES
1016 Specify the maximum number of NUMA Nodes available on the target
1017 system. Increases memory reserved to accomodate various tables.
1020 config HAVE_ARCH_BOOTMEM_NODE
1022 depends on X86_32 && NUMA
1024 config ARCH_HAVE_MEMORY_PRESENT
1026 depends on X86_32 && DISCONTIGMEM
1028 config NEED_NODE_MEMMAP_SIZE
1030 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1032 config HAVE_ARCH_ALLOC_REMAP
1034 depends on X86_32 && NUMA
1036 config ARCH_FLATMEM_ENABLE
1038 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
1040 config ARCH_DISCONTIGMEM_ENABLE
1042 depends on NUMA && X86_32
1044 config ARCH_DISCONTIGMEM_DEFAULT
1046 depends on NUMA && X86_32
1048 config ARCH_SPARSEMEM_DEFAULT
1052 config ARCH_SPARSEMEM_ENABLE
1054 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1055 select SPARSEMEM_STATIC if X86_32
1056 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1058 config ARCH_SELECT_MEMORY_MODEL
1060 depends on ARCH_SPARSEMEM_ENABLE
1062 config ARCH_MEMORY_PROBE
1064 depends on MEMORY_HOTPLUG
1069 bool "Allocate 3rd-level pagetables from highmem"
1070 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1072 The VM uses one page table entry for each page of physical memory.
1073 For systems with a lot of RAM, this can be wasteful of precious
1074 low memory. Setting this option will put user-space page table
1075 entries in high memory.
1077 config MATH_EMULATION
1079 prompt "Math emulation" if X86_32
1081 Linux can emulate a math coprocessor (used for floating point
1082 operations) if you don't have one. 486DX and Pentium processors have
1083 a math coprocessor built in, 486SX and 386 do not, unless you added
1084 a 487DX or 387, respectively. (The messages during boot time can
1085 give you some hints here ["man dmesg"].) Everyone needs either a
1086 coprocessor or this emulation.
1088 If you don't have a math coprocessor, you need to say Y here; if you
1089 say Y here even though you have a coprocessor, the coprocessor will
1090 be used nevertheless. (This behavior can be changed with the kernel
1091 command line option "no387", which comes handy if your coprocessor
1092 is broken. Try "man bootparam" or see the documentation of your boot
1093 loader (lilo or loadlin) about how to pass options to the kernel at
1094 boot time.) This means that it is a good idea to say Y here if you
1095 intend to use this kernel on different machines.
1097 More information about the internals of the Linux math coprocessor
1098 emulation can be found in <file:arch/x86/math-emu/README>.
1100 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1101 kernel, it won't hurt.
1104 bool "MTRR (Memory Type Range Register) support"
1106 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1107 the Memory Type Range Registers (MTRRs) may be used to control
1108 processor access to memory ranges. This is most useful if you have
1109 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1110 allows bus write transfers to be combined into a larger transfer
1111 before bursting over the PCI/AGP bus. This can increase performance
1112 of image write operations 2.5 times or more. Saying Y here creates a
1113 /proc/mtrr file which may be used to manipulate your processor's
1114 MTRRs. Typically the X server should use this.
1116 This code has a reasonably generic interface so that similar
1117 control registers on other processors can be easily supported
1120 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1121 Registers (ARRs) which provide a similar functionality to MTRRs. For
1122 these, the ARRs are used to emulate the MTRRs.
1123 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1124 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1125 write-combining. All of these processors are supported by this code
1126 and it makes sense to say Y here if you have one of them.
1128 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1129 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1130 can lead to all sorts of problems, so it's good to say Y here.
1132 You can safely say Y even if your machine doesn't have MTRRs, you'll
1133 just add about 9 KB to your kernel.
1135 See <file:Documentation/mtrr.txt> for more information.
1137 config MTRR_SANITIZER
1139 prompt "MTRR cleanup support"
1142 Convert MTRR layout from continuous to discrete, so some X driver
1143 could add WB entries.
1145 Say N here if you see bootup problems (boot crash, boot hang,
1146 spontaneous reboots).
1148 Could be disabled with disable_mtrr_cleanup. Also mtrr_chunk_size
1149 could be used to send largest mtrr entry size for continuous block
1150 to hold holes (aka. UC entries)
1154 config MTRR_SANITIZER_ENABLE_DEFAULT
1155 int "MTRR cleanup enable value (0-1)"
1158 depends on MTRR_SANITIZER
1160 Enable mtrr cleanup default value
1162 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1163 int "MTRR cleanup spare reg num (0-7)"
1166 depends on MTRR_SANITIZER
1168 mtrr cleanup spare entries default, it can be changed via
1173 prompt "x86 PAT support"
1176 Use PAT attributes to setup page level cache control.
1178 PATs are the modern equivalents of MTRRs and are much more
1179 flexible than MTRRs.
1181 Say N here if you see bootup problems (boot crash, boot hang,
1182 spontaneous reboots) or a non-working video driver.
1188 prompt "EFI runtime service support"
1191 This enables the kernel to use EFI runtime services that are
1192 available (such as the EFI variable services).
1194 This option is only useful on systems that have EFI firmware.
1195 In addition, you should use the latest ELILO loader available
1196 at <http://elilo.sourceforge.net> in order to take advantage
1197 of EFI runtime services. However, even with this option, the
1198 resultant kernel should continue to boot on existing non-EFI
1203 prompt "Enable kernel irq balancing"
1204 depends on X86_32 && SMP && X86_IO_APIC
1206 The default yes will allow the kernel to do irq load balancing.
1207 Saying no will keep the kernel from doing irq load balancing.
1211 prompt "Enable seccomp to safely compute untrusted bytecode"
1214 This kernel feature is useful for number crunching applications
1215 that may need to compute untrusted bytecode during their
1216 execution. By using pipes or other transports made available to
1217 the process as file descriptors supporting the read/write
1218 syscalls, it's possible to isolate those applications in
1219 their own address space using seccomp. Once seccomp is
1220 enabled via /proc/<pid>/seccomp, it cannot be disabled
1221 and the task is only allowed to execute a few safe syscalls
1222 defined by each seccomp mode.
1224 If unsure, say Y. Only embedded should say N here.
1226 config CC_STACKPROTECTOR
1227 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1228 depends on X86_64 && EXPERIMENTAL && BROKEN
1230 This option turns on the -fstack-protector GCC feature. This
1231 feature puts, at the beginning of critical functions, a canary
1232 value on the stack just before the return address, and validates
1233 the value just before actually returning. Stack based buffer
1234 overflows (that need to overwrite this return address) now also
1235 overwrite the canary, which gets detected and the attack is then
1236 neutralized via a kernel panic.
1238 This feature requires gcc version 4.2 or above, or a distribution
1239 gcc with the feature backported. Older versions are automatically
1240 detected and for those versions, this configuration option is ignored.
1242 config CC_STACKPROTECTOR_ALL
1243 bool "Use stack-protector for all functions"
1244 depends on CC_STACKPROTECTOR
1246 Normally, GCC only inserts the canary value protection for
1247 functions that use large-ish on-stack buffers. By enabling
1248 this option, GCC will be asked to do this for ALL functions.
1250 source kernel/Kconfig.hz
1253 bool "kexec system call"
1254 depends on X86_BIOS_REBOOT
1256 kexec is a system call that implements the ability to shutdown your
1257 current kernel, and to start another kernel. It is like a reboot
1258 but it is independent of the system firmware. And like a reboot
1259 you can start any kernel with it, not just Linux.
1261 The name comes from the similarity to the exec system call.
1263 It is an ongoing process to be certain the hardware in a machine
1264 is properly shutdown, so do not be surprised if this code does not
1265 initially work for you. It may help to enable device hotplugging
1266 support. As of this writing the exact hardware interface is
1267 strongly in flux, so no good recommendation can be made.
1270 bool "kernel crash dumps (EXPERIMENTAL)"
1271 depends on X86_64 || (X86_32 && HIGHMEM)
1273 Generate crash dump after being started by kexec.
1274 This should be normally only set in special crash dump kernels
1275 which are loaded in the main kernel with kexec-tools into
1276 a specially reserved region and then later executed after
1277 a crash by kdump/kexec. The crash dump kernel must be compiled
1278 to a memory address not used by the main kernel or BIOS using
1279 PHYSICAL_START, or it must be built as a relocatable image
1280 (CONFIG_RELOCATABLE=y).
1281 For more details see Documentation/kdump/kdump.txt
1283 config PHYSICAL_START
1284 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1285 default "0x1000000" if X86_NUMAQ
1286 default "0x200000" if X86_64
1289 This gives the physical address where the kernel is loaded.
1291 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1292 bzImage will decompress itself to above physical address and
1293 run from there. Otherwise, bzImage will run from the address where
1294 it has been loaded by the boot loader and will ignore above physical
1297 In normal kdump cases one does not have to set/change this option
1298 as now bzImage can be compiled as a completely relocatable image
1299 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1300 address. This option is mainly useful for the folks who don't want
1301 to use a bzImage for capturing the crash dump and want to use a
1302 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1303 to be specifically compiled to run from a specific memory area
1304 (normally a reserved region) and this option comes handy.
1306 So if you are using bzImage for capturing the crash dump, leave
1307 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1308 Otherwise if you plan to use vmlinux for capturing the crash dump
1309 change this value to start of the reserved region (Typically 16MB
1310 0x1000000). In other words, it can be set based on the "X" value as
1311 specified in the "crashkernel=YM@XM" command line boot parameter
1312 passed to the panic-ed kernel. Typically this parameter is set as
1313 crashkernel=64M@16M. Please take a look at
1314 Documentation/kdump/kdump.txt for more details about crash dumps.
1316 Usage of bzImage for capturing the crash dump is recommended as
1317 one does not have to build two kernels. Same kernel can be used
1318 as production kernel and capture kernel. Above option should have
1319 gone away after relocatable bzImage support is introduced. But it
1320 is present because there are users out there who continue to use
1321 vmlinux for dump capture. This option should go away down the
1324 Don't change this unless you know what you are doing.
1327 bool "Build a relocatable kernel (EXPERIMENTAL)"
1328 depends on EXPERIMENTAL
1330 This builds a kernel image that retains relocation information
1331 so it can be loaded someplace besides the default 1MB.
1332 The relocations tend to make the kernel binary about 10% larger,
1333 but are discarded at runtime.
1335 One use is for the kexec on panic case where the recovery kernel
1336 must live at a different physical address than the primary
1339 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1340 it has been loaded at and the compile time physical address
1341 (CONFIG_PHYSICAL_START) is ignored.
1343 config PHYSICAL_ALIGN
1345 prompt "Alignment value to which kernel should be aligned" if X86_32
1346 default "0x100000" if X86_32
1347 default "0x200000" if X86_64
1348 range 0x2000 0x400000
1350 This value puts the alignment restrictions on physical address
1351 where kernel is loaded and run from. Kernel is compiled for an
1352 address which meets above alignment restriction.
1354 If bootloader loads the kernel at a non-aligned address and
1355 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1356 address aligned to above value and run from there.
1358 If bootloader loads the kernel at a non-aligned address and
1359 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1360 load address and decompress itself to the address it has been
1361 compiled for and run from there. The address for which kernel is
1362 compiled already meets above alignment restrictions. Hence the
1363 end result is that kernel runs from a physical address meeting
1364 above alignment restrictions.
1366 Don't change this unless you know what you are doing.
1369 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1370 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1372 Say Y here to experiment with turning CPUs off and on, and to
1373 enable suspend on SMP systems. CPUs can be controlled through
1374 /sys/devices/system/cpu.
1375 Say N if you want to disable CPU hotplug and don't need to
1380 prompt "Compat VDSO support"
1381 depends on X86_32 || IA32_EMULATION
1383 Map the 32-bit VDSO to the predictable old-style address too.
1385 Say N here if you are running a sufficiently recent glibc
1386 version (2.3.3 or later), to remove the high-mapped
1387 VDSO mapping and to exclusively use the randomized VDSO.
1393 config ARCH_ENABLE_MEMORY_HOTPLUG
1395 depends on X86_64 || (X86_32 && HIGHMEM)
1397 config HAVE_ARCH_EARLY_PFN_TO_NID
1401 menu "Power management options"
1402 depends on !X86_VOYAGER
1404 config ARCH_HIBERNATION_HEADER
1406 depends on X86_64 && HIBERNATION
1408 source "kernel/power/Kconfig"
1410 source "drivers/acpi/Kconfig"
1415 depends on APM || APM_MODULE
1418 tristate "APM (Advanced Power Management) BIOS support"
1419 depends on X86_32 && PM_SLEEP
1421 APM is a BIOS specification for saving power using several different
1422 techniques. This is mostly useful for battery powered laptops with
1423 APM compliant BIOSes. If you say Y here, the system time will be
1424 reset after a RESUME operation, the /proc/apm device will provide
1425 battery status information, and user-space programs will receive
1426 notification of APM "events" (e.g. battery status change).
1428 If you select "Y" here, you can disable actual use of the APM
1429 BIOS by passing the "apm=off" option to the kernel at boot time.
1431 Note that the APM support is almost completely disabled for
1432 machines with more than one CPU.
1434 In order to use APM, you will need supporting software. For location
1435 and more information, read <file:Documentation/power/pm.txt> and the
1436 Battery Powered Linux mini-HOWTO, available from
1437 <http://www.tldp.org/docs.html#howto>.
1439 This driver does not spin down disk drives (see the hdparm(8)
1440 manpage ("man 8 hdparm") for that), and it doesn't turn off
1441 VESA-compliant "green" monitors.
1443 This driver does not support the TI 4000M TravelMate and the ACER
1444 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1445 desktop machines also don't have compliant BIOSes, and this driver
1446 may cause those machines to panic during the boot phase.
1448 Generally, if you don't have a battery in your machine, there isn't
1449 much point in using this driver and you should say N. If you get
1450 random kernel OOPSes or reboots that don't seem to be related to
1451 anything, try disabling/enabling this option (or disabling/enabling
1454 Some other things you should try when experiencing seemingly random,
1457 1) make sure that you have enough swap space and that it is
1459 2) pass the "no-hlt" option to the kernel
1460 3) switch on floating point emulation in the kernel and pass
1461 the "no387" option to the kernel
1462 4) pass the "floppy=nodma" option to the kernel
1463 5) pass the "mem=4M" option to the kernel (thereby disabling
1464 all but the first 4 MB of RAM)
1465 6) make sure that the CPU is not over clocked.
1466 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1467 8) disable the cache from your BIOS settings
1468 9) install a fan for the video card or exchange video RAM
1469 10) install a better fan for the CPU
1470 11) exchange RAM chips
1471 12) exchange the motherboard.
1473 To compile this driver as a module, choose M here: the
1474 module will be called apm.
1478 config APM_IGNORE_USER_SUSPEND
1479 bool "Ignore USER SUSPEND"
1481 This option will ignore USER SUSPEND requests. On machines with a
1482 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1483 series notebooks, it is necessary to say Y because of a BIOS bug.
1485 config APM_DO_ENABLE
1486 bool "Enable PM at boot time"
1488 Enable APM features at boot time. From page 36 of the APM BIOS
1489 specification: "When disabled, the APM BIOS does not automatically
1490 power manage devices, enter the Standby State, enter the Suspend
1491 State, or take power saving steps in response to CPU Idle calls."
1492 This driver will make CPU Idle calls when Linux is idle (unless this
1493 feature is turned off -- see "Do CPU IDLE calls", below). This
1494 should always save battery power, but more complicated APM features
1495 will be dependent on your BIOS implementation. You may need to turn
1496 this option off if your computer hangs at boot time when using APM
1497 support, or if it beeps continuously instead of suspending. Turn
1498 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1499 T400CDT. This is off by default since most machines do fine without
1503 bool "Make CPU Idle calls when idle"
1505 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1506 On some machines, this can activate improved power savings, such as
1507 a slowed CPU clock rate, when the machine is idle. These idle calls
1508 are made after the idle loop has run for some length of time (e.g.,
1509 333 mS). On some machines, this will cause a hang at boot time or
1510 whenever the CPU becomes idle. (On machines with more than one CPU,
1511 this option does nothing.)
1513 config APM_DISPLAY_BLANK
1514 bool "Enable console blanking using APM"
1516 Enable console blanking using the APM. Some laptops can use this to
1517 turn off the LCD backlight when the screen blanker of the Linux
1518 virtual console blanks the screen. Note that this is only used by
1519 the virtual console screen blanker, and won't turn off the backlight
1520 when using the X Window system. This also doesn't have anything to
1521 do with your VESA-compliant power-saving monitor. Further, this
1522 option doesn't work for all laptops -- it might not turn off your
1523 backlight at all, or it might print a lot of errors to the console,
1524 especially if you are using gpm.
1526 config APM_ALLOW_INTS
1527 bool "Allow interrupts during APM BIOS calls"
1529 Normally we disable external interrupts while we are making calls to
1530 the APM BIOS as a measure to lessen the effects of a badly behaving
1531 BIOS implementation. The BIOS should reenable interrupts if it
1532 needs to. Unfortunately, some BIOSes do not -- especially those in
1533 many of the newer IBM Thinkpads. If you experience hangs when you
1534 suspend, try setting this to Y. Otherwise, say N.
1536 config APM_REAL_MODE_POWER_OFF
1537 bool "Use real mode APM BIOS call to power off"
1539 Use real mode APM BIOS calls to switch off the computer. This is
1540 a work-around for a number of buggy BIOSes. Switch this option on if
1541 your computer crashes instead of powering off properly.
1545 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1547 source "drivers/cpuidle/Kconfig"
1552 menu "Bus options (PCI etc.)"
1557 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1559 Find out whether you have a PCI motherboard. PCI is the name of a
1560 bus system, i.e. the way the CPU talks to the other stuff inside
1561 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1562 VESA. If you have PCI, say Y, otherwise N.
1565 prompt "PCI access mode"
1566 depends on X86_32 && PCI
1569 On PCI systems, the BIOS can be used to detect the PCI devices and
1570 determine their configuration. However, some old PCI motherboards
1571 have BIOS bugs and may crash if this is done. Also, some embedded
1572 PCI-based systems don't have any BIOS at all. Linux can also try to
1573 detect the PCI hardware directly without using the BIOS.
1575 With this option, you can specify how Linux should detect the
1576 PCI devices. If you choose "BIOS", the BIOS will be used,
1577 if you choose "Direct", the BIOS won't be used, and if you
1578 choose "MMConfig", then PCI Express MMCONFIG will be used.
1579 If you choose "Any", the kernel will try MMCONFIG, then the
1580 direct access method and falls back to the BIOS if that doesn't
1581 work. If unsure, go with the default, which is "Any".
1586 config PCI_GOMMCONFIG
1603 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1605 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1608 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1612 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1616 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1623 bool "Support mmconfig PCI config space access"
1624 depends on X86_64 && PCI && ACPI
1627 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1628 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1630 DMA remapping (DMAR) devices support enables independent address
1631 translations for Direct Memory Access (DMA) from devices.
1632 These DMA remapping devices are reported via ACPI tables
1633 and include PCI device scope covered by these DMA
1638 prompt "Support for Graphics workaround"
1641 Current Graphics drivers tend to use physical address
1642 for DMA and avoid using DMA APIs. Setting this config
1643 option permits the IOMMU driver to set a unity map for
1644 all the OS-visible memory. Hence the driver can continue
1645 to use physical addresses for DMA.
1647 config DMAR_FLOPPY_WA
1651 Floppy disk drivers are know to bypass DMA API calls
1652 thereby failing to work when IOMMU is enabled. This
1653 workaround will setup a 1:1 mapping for the first
1654 16M to make floppy (an ISA device) work.
1656 source "drivers/pci/pcie/Kconfig"
1658 source "drivers/pci/Kconfig"
1660 # x86_64 have no ISA slots, but do have ISA-style DMA.
1668 depends on !X86_VOYAGER
1670 Find out whether you have ISA slots on your motherboard. ISA is the
1671 name of a bus system, i.e. the way the CPU talks to the other stuff
1672 inside your box. Other bus systems are PCI, EISA, MicroChannel
1673 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1674 newer boards don't support it. If you have ISA, say Y, otherwise N.
1680 The Extended Industry Standard Architecture (EISA) bus was
1681 developed as an open alternative to the IBM MicroChannel bus.
1683 The EISA bus provided some of the features of the IBM MicroChannel
1684 bus while maintaining backward compatibility with cards made for
1685 the older ISA bus. The EISA bus saw limited use between 1988 and
1686 1995 when it was made obsolete by the PCI bus.
1688 Say Y here if you are building a kernel for an EISA-based machine.
1692 source "drivers/eisa/Kconfig"
1695 bool "MCA support" if !X86_VOYAGER
1696 default y if X86_VOYAGER
1698 MicroChannel Architecture is found in some IBM PS/2 machines and
1699 laptops. It is a bus system similar to PCI or ISA. See
1700 <file:Documentation/mca.txt> (and especially the web page given
1701 there) before attempting to build an MCA bus kernel.
1703 source "drivers/mca/Kconfig"
1706 tristate "NatSemi SCx200 support"
1707 depends on !X86_VOYAGER
1709 This provides basic support for National Semiconductor's
1710 (now AMD's) Geode processors. The driver probes for the
1711 PCI-IDs of several on-chip devices, so its a good dependency
1712 for other scx200_* drivers.
1714 If compiled as a module, the driver is named scx200.
1716 config SCx200HR_TIMER
1717 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1718 depends on SCx200 && GENERIC_TIME
1721 This driver provides a clocksource built upon the on-chip
1722 27MHz high-resolution timer. Its also a workaround for
1723 NSC Geode SC-1100's buggy TSC, which loses time when the
1724 processor goes idle (as is done by the scheduler). The
1725 other workaround is idle=poll boot option.
1727 config GEODE_MFGPT_TIMER
1729 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1730 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1732 This driver provides a clock event source based on the MFGPT
1733 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1734 MFGPTs have a better resolution and max interval than the
1735 generic PIT, and are suitable for use as high-res timers.
1738 bool "One Laptop Per Child support"
1741 Add support for detecting the unique features of the OLPC
1748 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1750 source "drivers/pcmcia/Kconfig"
1752 source "drivers/pci/hotplug/Kconfig"
1757 menu "Executable file formats / Emulations"
1759 source "fs/Kconfig.binfmt"
1761 config IA32_EMULATION
1762 bool "IA32 Emulation"
1764 select COMPAT_BINFMT_ELF
1766 Include code to run 32-bit programs under a 64-bit kernel. You should
1767 likely turn this on, unless you're 100% sure that you don't have any
1768 32-bit programs left.
1771 tristate "IA32 a.out support"
1772 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1774 Support old a.out binaries in the 32bit emulation.
1778 depends on IA32_EMULATION
1780 config COMPAT_FOR_U64_ALIGNMENT
1784 config SYSVIPC_COMPAT
1786 depends on X86_64 && COMPAT && SYSVIPC
1791 source "net/Kconfig"
1793 source "drivers/Kconfig"
1795 source "drivers/firmware/Kconfig"
1799 source "arch/x86/Kconfig.debug"
1801 source "security/Kconfig"
1803 source "crypto/Kconfig"
1805 source "arch/x86/kvm/Kconfig"
1807 source "lib/Kconfig"
projects / linux-2.6 / blob