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_VISWS || X86_VOYAGER)) || X86_64
187 config X86_BIOS_REBOOT
189 depends on !X86_VISWS && !X86_VOYAGER
192 config X86_TRAMPOLINE
194 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
199 source "init/Kconfig"
201 menu "Processor type and features"
203 source "kernel/time/Kconfig"
206 bool "Symmetric multi-processing support"
208 This enables support for systems with more than one CPU. If you have
209 a system with only one CPU, like most personal computers, say N. If
210 you have a system with more than one CPU, say Y.
212 If you say N here, the kernel will run on single and multiprocessor
213 machines, but will use only one CPU of a multiprocessor machine. If
214 you say Y here, the kernel will run on many, but not all,
215 singleprocessor machines. On a singleprocessor machine, the kernel
216 will run faster if you say N here.
218 Note that if you say Y here and choose architecture "586" or
219 "Pentium" under "Processor family", the kernel will not work on 486
220 architectures. Similarly, multiprocessor kernels for the "PPro"
221 architecture may not work on all Pentium based boards.
223 People using multiprocessor machines who say Y here should also say
224 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
225 Management" code will be disabled if you say Y here.
227 See also <file:Documentation/i386/IO-APIC.txt>,
228 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
229 <http://www.tldp.org/docs.html#howto>.
231 If you don't know what to do here, say N.
233 config X86_FIND_SMP_CONFIG
235 depends on X86_MPPARSE || X86_VOYAGER || X86_VISWS
241 bool "Enable MPS table"
242 depends on X86_LOCAL_APIC && !X86_VISWS
244 For old smp systems that do not have proper acpi support. Newer systems
245 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
251 depends on X86_LOCAL_APIC && !X86_VISWS
255 prompt "Subarchitecture Type"
261 Choose this option if your computer is a standard PC or compatible.
267 Select this for an AMD Elan processor.
269 Do not use this option for K6/Athlon/Opteron processors!
271 If unsure, choose "PC-compatible" instead.
275 depends on X86_32 && (SMP || BROKEN) && !PCI
277 Voyager is an MCA-based 32-way capable SMP architecture proprietary
278 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
282 If you do not specifically know you have a Voyager based machine,
283 say N here, otherwise the kernel you build will not be bootable.
286 bool "SGI 320/540 (Visual Workstation)"
287 depends on X86_32 && !PCI
289 The SGI Visual Workstation series is an IA32-based workstation
290 based on SGI systems chips with some legacy PC hardware attached.
292 Say Y here to create a kernel to run on the SGI 320 or 540.
294 A kernel compiled for the Visual Workstation will not run on PCs
295 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
297 config X86_GENERICARCH
298 bool "Generic architecture"
301 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
302 subarchitectures. It is intended for a generic binary kernel.
303 if you select them all, kernel will probe it one by one. and will
309 bool "NUMAQ (IBM/Sequent)"
310 depends on SMP && X86_32 && PCI && X86_MPPARSE
313 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
314 NUMA multiquad box. This changes the way that processors are
315 bootstrapped, and uses Clustered Logical APIC addressing mode instead
316 of Flat Logical. You will need a new lynxer.elf file to flash your
317 firmware with - send email to <Martin.Bligh@us.ibm.com>.
320 bool "Summit/EXA (IBM x440)"
321 depends on X86_32 && SMP
323 This option is needed for IBM systems that use the Summit/EXA chipset.
324 In particular, it is needed for the x440.
327 bool "Support for Unisys ES7000 IA32 series"
328 depends on X86_32 && SMP
330 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
331 supposed to run on an IA32-based Unisys ES7000 system.
334 bool "Support for big SMP systems with more than 8 CPUs"
335 depends on X86_32 && SMP
337 This option is needed for the systems that have more than 8 CPUs
338 and if the system is not of any sub-arch type above.
343 bool "RDC R-321x SoC"
346 select X86_REBOOTFIXUPS
352 This option is needed for RDC R-321x system-on-chip, also known
354 If you don't have one of these chips, you should say N here.
357 bool "Support for ScaleMP vSMP"
359 depends on X86_64 && !PCI
361 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
362 supposed to run on these EM64T-based machines. Only choose this option
363 if you have one of these machines.
367 config SCHED_NO_NO_OMIT_FRAME_POINTER
369 prompt "Single-depth WCHAN output"
372 Calculate simpler /proc/<PID>/wchan values. If this option
373 is disabled then wchan values will recurse back to the
374 caller function. This provides more accurate wchan values,
375 at the expense of slightly more scheduling overhead.
377 If in doubt, say "Y".
379 menuconfig PARAVIRT_GUEST
380 bool "Paravirtualized guest support"
382 Say Y here to get to see options related to running Linux under
383 various hypervisors. This option alone does not add any kernel code.
385 If you say N, all options in this submenu will be skipped and disabled.
389 source "arch/x86/xen/Kconfig"
392 bool "VMI Guest support"
395 depends on !(X86_VISWS || X86_VOYAGER)
397 VMI provides a paravirtualized interface to the VMware ESX server
398 (it could be used by other hypervisors in theory too, but is not
399 at the moment), by linking the kernel to a GPL-ed ROM module
400 provided by the hypervisor.
403 bool "KVM paravirtualized clock"
405 select PARAVIRT_CLOCK
406 depends on !(X86_VISWS || X86_VOYAGER)
408 Turning on this option will allow you to run a paravirtualized clock
409 when running over the KVM hypervisor. Instead of relying on a PIT
410 (or probably other) emulation by the underlying device model, the host
411 provides the guest with timing infrastructure such as time of day, and
415 bool "KVM Guest support"
417 depends on !(X86_VISWS || X86_VOYAGER)
419 This option enables various optimizations for running under the KVM
422 source "arch/x86/lguest/Kconfig"
425 bool "Enable paravirtualization code"
426 depends on !(X86_VISWS || X86_VOYAGER)
428 This changes the kernel so it can modify itself when it is run
429 under a hypervisor, potentially improving performance significantly
430 over full virtualization. However, when run without a hypervisor
431 the kernel is theoretically slower and slightly larger.
433 config PARAVIRT_CLOCK
444 This option adds a kernel parameter 'memtest', which allows memtest
446 memtest=0, mean disabled; -- default
447 memtest=1, mean do 1 test pattern;
449 memtest=4, mean do 4 test patterns.
450 If you are unsure how to answer this question, answer Y.
454 depends on X86_32 && ACPI && NUMA && X86_GENERICARCH
457 config HAVE_ARCH_PARSE_SRAT
461 config X86_SUMMIT_NUMA
463 depends on X86_32 && NUMA && X86_GENERICARCH
465 config X86_CYCLONE_TIMER
467 depends on X86_GENERICARCH
469 config ES7000_CLUSTERED_APIC
471 depends on SMP && X86_ES7000 && MPENTIUMIII
473 source "arch/x86/Kconfig.cpu"
477 prompt "HPET Timer Support" if X86_32
479 Use the IA-PC HPET (High Precision Event Timer) to manage
480 time in preference to the PIT and RTC, if a HPET is
482 HPET is the next generation timer replacing legacy 8254s.
483 The HPET provides a stable time base on SMP
484 systems, unlike the TSC, but it is more expensive to access,
485 as it is off-chip. You can find the HPET spec at
486 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
488 You can safely choose Y here. However, HPET will only be
489 activated if the platform and the BIOS support this feature.
490 Otherwise the 8254 will be used for timing services.
492 Choose N to continue using the legacy 8254 timer.
494 config HPET_EMULATE_RTC
496 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
498 # Mark as embedded because too many people got it wrong.
499 # The code disables itself when not needed.
502 bool "Enable DMI scanning" if EMBEDDED
504 Enabled scanning of DMI to identify machine quirks. Say Y
505 here unless you have verified that your setup is not
506 affected by entries in the DMI blacklist. Required by PNP
510 bool "GART IOMMU support" if EMBEDDED
514 depends on X86_64 && PCI
516 Support for full DMA access of devices with 32bit memory access only
517 on systems with more than 3GB. This is usually needed for USB,
518 sound, many IDE/SATA chipsets and some other devices.
519 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
520 based hardware IOMMU and a software bounce buffer based IOMMU used
521 on Intel systems and as fallback.
522 The code is only active when needed (enough memory and limited
523 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
527 bool "IBM Calgary IOMMU support"
529 depends on X86_64 && PCI && EXPERIMENTAL
531 Support for hardware IOMMUs in IBM's xSeries x366 and x460
532 systems. Needed to run systems with more than 3GB of memory
533 properly with 32-bit PCI devices that do not support DAC
534 (Double Address Cycle). Calgary also supports bus level
535 isolation, where all DMAs pass through the IOMMU. This
536 prevents them from going anywhere except their intended
537 destination. This catches hard-to-find kernel bugs and
538 mis-behaving drivers and devices that do not use the DMA-API
539 properly to set up their DMA buffers. The IOMMU can be
540 turned off at boot time with the iommu=off parameter.
541 Normally the kernel will make the right choice by itself.
544 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
546 prompt "Should Calgary be enabled by default?"
547 depends on CALGARY_IOMMU
549 Should Calgary be enabled by default? if you choose 'y', Calgary
550 will be used (if it exists). If you choose 'n', Calgary will not be
551 used even if it exists. If you choose 'n' and would like to use
552 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
556 bool "AMD IOMMU support"
558 depends on X86_64 && PCI && ACPI
560 With this option you can enable support for AMD IOMMU hardware in
561 your system. An IOMMU is a hardware component which provides
562 remapping of DMA memory accesses from devices. With an AMD IOMMU you
563 can isolate the the DMA memory of different devices and protect the
564 system from misbehaving device drivers or hardware.
566 You can find out if your system has an AMD IOMMU if you look into
567 your BIOS for an option to enable it or if you have an IVRS ACPI
570 # need this always selected by IOMMU for the VIA workaround
574 Support for software bounce buffers used on x86-64 systems
575 which don't have a hardware IOMMU (e.g. the current generation
576 of Intel's x86-64 CPUs). Using this PCI devices which can only
577 access 32-bits of memory can be used on systems with more than
578 3 GB of memory. If unsure, say Y.
581 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB)
583 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
584 depends on X86_64 && SMP
587 Configure maximum number of CPUS and NUMA Nodes for this architecture.
598 int "Maximum number of CPUs (2-4096)"
601 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
604 This allows you to specify the maximum number of CPUs which this
605 kernel will support. The maximum supported value is 4096 and the
606 minimum value which makes sense is 2.
608 This is purely to save memory - each supported CPU adds
609 approximately eight kilobytes to the kernel image.
613 bool "SMT (Hyperthreading) scheduler support"
616 SMT scheduler support improves the CPU scheduler's decision making
617 when dealing with Intel Pentium 4 chips with HyperThreading at a
618 cost of slightly increased overhead in some places. If unsure say
623 prompt "Multi-core scheduler support"
626 Multi-core scheduler support improves the CPU scheduler's decision
627 making when dealing with multi-core CPU chips at a cost of slightly
628 increased overhead in some places. If unsure say N here.
630 source "kernel/Kconfig.preempt"
633 bool "Local APIC support on uniprocessors"
634 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
636 A local APIC (Advanced Programmable Interrupt Controller) is an
637 integrated interrupt controller in the CPU. If you have a single-CPU
638 system which has a processor with a local APIC, you can say Y here to
639 enable and use it. If you say Y here even though your machine doesn't
640 have a local APIC, then the kernel will still run with no slowdown at
641 all. The local APIC supports CPU-generated self-interrupts (timer,
642 performance counters), and the NMI watchdog which detects hard
646 bool "IO-APIC support on uniprocessors"
647 depends on X86_UP_APIC
649 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
650 SMP-capable replacement for PC-style interrupt controllers. Most
651 SMP systems and many recent uniprocessor systems have one.
653 If you have a single-CPU system with an IO-APIC, you can say Y here
654 to use it. If you say Y here even though your machine doesn't have
655 an IO-APIC, then the kernel will still run with no slowdown at all.
657 config X86_LOCAL_APIC
659 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
663 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
665 config X86_VISWS_APIC
667 depends on X86_32 && X86_VISWS
670 bool "Machine Check Exception"
671 depends on !X86_VOYAGER
673 Machine Check Exception support allows the processor to notify the
674 kernel if it detects a problem (e.g. overheating, component failure).
675 The action the kernel takes depends on the severity of the problem,
676 ranging from a warning message on the console, to halting the machine.
677 Your processor must be a Pentium or newer to support this - check the
678 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
679 have a design flaw which leads to false MCE events - hence MCE is
680 disabled on all P5 processors, unless explicitly enabled with "mce"
681 as a boot argument. Similarly, if MCE is built in and creates a
682 problem on some new non-standard machine, you can boot with "nomce"
683 to disable it. MCE support simply ignores non-MCE processors like
684 the 386 and 486, so nearly everyone can say Y here.
688 prompt "Intel MCE features"
689 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
691 Additional support for intel specific MCE features such as
696 prompt "AMD MCE features"
697 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
699 Additional support for AMD specific MCE features such as
700 the DRAM Error Threshold.
702 config X86_MCE_NONFATAL
703 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
704 depends on X86_32 && X86_MCE
706 Enabling this feature starts a timer that triggers every 5 seconds which
707 will look at the machine check registers to see if anything happened.
708 Non-fatal problems automatically get corrected (but still logged).
709 Disable this if you don't want to see these messages.
710 Seeing the messages this option prints out may be indicative of dying
711 or out-of-spec (ie, overclocked) hardware.
712 This option only does something on certain CPUs.
713 (AMD Athlon/Duron and Intel Pentium 4)
715 config X86_MCE_P4THERMAL
716 bool "check for P4 thermal throttling interrupt."
717 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
719 Enabling this feature will cause a message to be printed when the P4
720 enters thermal throttling.
723 bool "Enable VM86 support" if EMBEDDED
727 This option is required by programs like DOSEMU to run 16-bit legacy
728 code on X86 processors. It also may be needed by software like
729 XFree86 to initialize some video cards via BIOS. Disabling this
730 option saves about 6k.
733 tristate "Toshiba Laptop support"
736 This adds a driver to safely access the System Management Mode of
737 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
738 not work on models with a Phoenix BIOS. The System Management Mode
739 is used to set the BIOS and power saving options on Toshiba portables.
741 For information on utilities to make use of this driver see the
742 Toshiba Linux utilities web site at:
743 <http://www.buzzard.org.uk/toshiba/>.
745 Say Y if you intend to run this kernel on a Toshiba portable.
749 tristate "Dell laptop support"
751 This adds a driver to safely access the System Management Mode
752 of the CPU on the Dell Inspiron 8000. The System Management Mode
753 is used to read cpu temperature and cooling fan status and to
754 control the fans on the I8K portables.
756 This driver has been tested only on the Inspiron 8000 but it may
757 also work with other Dell laptops. You can force loading on other
758 models by passing the parameter `force=1' to the module. Use at
761 For information on utilities to make use of this driver see the
762 I8K Linux utilities web site at:
763 <http://people.debian.org/~dz/i8k/>
765 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
768 config X86_REBOOTFIXUPS
770 prompt "Enable X86 board specific fixups for reboot"
771 depends on X86_32 && X86
773 This enables chipset and/or board specific fixups to be done
774 in order to get reboot to work correctly. This is only needed on
775 some combinations of hardware and BIOS. The symptom, for which
776 this config is intended, is when reboot ends with a stalled/hung
779 Currently, the only fixup is for the Geode machines using
780 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
782 Say Y if you want to enable the fixup. Currently, it's safe to
783 enable this option even if you don't need it.
787 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
790 If you say Y here, you will be able to update the microcode on
791 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
792 Pentium III, Pentium 4, Xeon etc. You will obviously need the
793 actual microcode binary data itself which is not shipped with the
796 For latest news and information on obtaining all the required
797 ingredients for this driver, check:
798 <http://www.urbanmyth.org/microcode/>.
800 To compile this driver as a module, choose M here: the
801 module will be called microcode.
803 config MICROCODE_OLD_INTERFACE
808 tristate "/dev/cpu/*/msr - Model-specific register support"
810 This device gives privileged processes access to the x86
811 Model-Specific Registers (MSRs). It is a character device with
812 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
813 MSR accesses are directed to a specific CPU on multi-processor
817 tristate "/dev/cpu/*/cpuid - CPU information support"
819 This device gives processes access to the x86 CPUID instruction to
820 be executed on a specific processor. It is a character device
821 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
825 prompt "High Memory Support"
826 default HIGHMEM4G if !X86_NUMAQ
827 default HIGHMEM64G if X86_NUMAQ
832 depends on !X86_NUMAQ
834 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
835 However, the address space of 32-bit x86 processors is only 4
836 Gigabytes large. That means that, if you have a large amount of
837 physical memory, not all of it can be "permanently mapped" by the
838 kernel. The physical memory that's not permanently mapped is called
841 If you are compiling a kernel which will never run on a machine with
842 more than 1 Gigabyte total physical RAM, answer "off" here (default
843 choice and suitable for most users). This will result in a "3GB/1GB"
844 split: 3GB are mapped so that each process sees a 3GB virtual memory
845 space and the remaining part of the 4GB virtual memory space is used
846 by the kernel to permanently map as much physical memory as
849 If the machine has between 1 and 4 Gigabytes physical RAM, then
852 If more than 4 Gigabytes is used then answer "64GB" here. This
853 selection turns Intel PAE (Physical Address Extension) mode on.
854 PAE implements 3-level paging on IA32 processors. PAE is fully
855 supported by Linux, PAE mode is implemented on all recent Intel
856 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
857 then the kernel will not boot on CPUs that don't support PAE!
859 The actual amount of total physical memory will either be
860 auto detected or can be forced by using a kernel command line option
861 such as "mem=256M". (Try "man bootparam" or see the documentation of
862 your boot loader (lilo or loadlin) about how to pass options to the
863 kernel at boot time.)
865 If unsure, say "off".
869 depends on !X86_NUMAQ
871 Select this if you have a 32-bit processor and between 1 and 4
872 gigabytes of physical RAM.
876 depends on !M386 && !M486
879 Select this if you have a 32-bit processor and more than 4
880 gigabytes of physical RAM.
885 depends on EXPERIMENTAL
886 prompt "Memory split" if EMBEDDED
890 Select the desired split between kernel and user memory.
892 If the address range available to the kernel is less than the
893 physical memory installed, the remaining memory will be available
894 as "high memory". Accessing high memory is a little more costly
895 than low memory, as it needs to be mapped into the kernel first.
896 Note that increasing the kernel address space limits the range
897 available to user programs, making the address space there
898 tighter. Selecting anything other than the default 3G/1G split
899 will also likely make your kernel incompatible with binary-only
902 If you are not absolutely sure what you are doing, leave this
906 bool "3G/1G user/kernel split"
907 config VMSPLIT_3G_OPT
909 bool "3G/1G user/kernel split (for full 1G low memory)"
911 bool "2G/2G user/kernel split"
912 config VMSPLIT_2G_OPT
914 bool "2G/2G user/kernel split (for full 2G low memory)"
916 bool "1G/3G user/kernel split"
921 default 0xB0000000 if VMSPLIT_3G_OPT
922 default 0x80000000 if VMSPLIT_2G
923 default 0x78000000 if VMSPLIT_2G_OPT
924 default 0x40000000 if VMSPLIT_1G
930 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
934 prompt "PAE (Physical Address Extension) Support"
935 depends on X86_32 && !HIGHMEM4G
936 select RESOURCES_64BIT
938 PAE is required for NX support, and furthermore enables
939 larger swapspace support for non-overcommit purposes. It
940 has the cost of more pagetable lookup overhead, and also
941 consumes more pagetable space per process.
943 # Common NUMA Features
945 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
947 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
949 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
951 Enable NUMA (Non Uniform Memory Access) support.
952 The kernel will try to allocate memory used by a CPU on the
953 local memory controller of the CPU and add some more
954 NUMA awareness to the kernel.
956 For i386 this is currently highly experimental and should be only
957 used for kernel development. It might also cause boot failures.
958 For x86_64 this is recommended on all multiprocessor Opteron systems.
959 If the system is EM64T, you should say N unless your system is
962 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
963 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
967 prompt "Old style AMD Opteron NUMA detection"
968 depends on X86_64 && NUMA && PCI
970 Enable K8 NUMA node topology detection. You should say Y here if
971 you have a multi processor AMD K8 system. This uses an old
972 method to read the NUMA configuration directly from the builtin
973 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
974 instead, which also takes priority if both are compiled in.
976 config X86_64_ACPI_NUMA
978 prompt "ACPI NUMA detection"
979 depends on X86_64 && NUMA && ACPI && PCI
982 Enable ACPI SRAT based node topology detection.
984 # Some NUMA nodes have memory ranges that span
985 # other nodes. Even though a pfn is valid and
986 # between a node's start and end pfns, it may not
987 # reside on that node. See memmap_init_zone()
989 config NODES_SPAN_OTHER_NODES
991 depends on X86_64_ACPI_NUMA
994 bool "NUMA emulation"
995 depends on X86_64 && NUMA
997 Enable NUMA emulation. A flat machine will be split
998 into virtual nodes when booted with "numa=fake=N", where N is the
999 number of nodes. This is only useful for debugging.
1010 int "Maximum NUMA Nodes (as a power of 2)"
1012 default "6" if X86_64
1013 default "4" if X86_NUMAQ
1015 depends on NEED_MULTIPLE_NODES
1017 Specify the maximum number of NUMA Nodes available on the target
1018 system. Increases memory reserved to accomodate various tables.
1021 config HAVE_ARCH_BOOTMEM_NODE
1023 depends on X86_32 && NUMA
1025 config ARCH_HAVE_MEMORY_PRESENT
1027 depends on X86_32 && DISCONTIGMEM
1029 config NEED_NODE_MEMMAP_SIZE
1031 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1033 config HAVE_ARCH_ALLOC_REMAP
1035 depends on X86_32 && NUMA
1037 config ARCH_FLATMEM_ENABLE
1039 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
1041 config ARCH_DISCONTIGMEM_ENABLE
1043 depends on NUMA && X86_32
1045 config ARCH_DISCONTIGMEM_DEFAULT
1047 depends on NUMA && X86_32
1049 config ARCH_SPARSEMEM_DEFAULT
1053 config ARCH_SPARSEMEM_ENABLE
1055 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1056 select SPARSEMEM_STATIC if X86_32
1057 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1059 config ARCH_SELECT_MEMORY_MODEL
1061 depends on ARCH_SPARSEMEM_ENABLE
1063 config ARCH_MEMORY_PROBE
1065 depends on MEMORY_HOTPLUG
1070 bool "Allocate 3rd-level pagetables from highmem"
1071 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1073 The VM uses one page table entry for each page of physical memory.
1074 For systems with a lot of RAM, this can be wasteful of precious
1075 low memory. Setting this option will put user-space page table
1076 entries in high memory.
1078 config MATH_EMULATION
1080 prompt "Math emulation" if X86_32
1082 Linux can emulate a math coprocessor (used for floating point
1083 operations) if you don't have one. 486DX and Pentium processors have
1084 a math coprocessor built in, 486SX and 386 do not, unless you added
1085 a 487DX or 387, respectively. (The messages during boot time can
1086 give you some hints here ["man dmesg"].) Everyone needs either a
1087 coprocessor or this emulation.
1089 If you don't have a math coprocessor, you need to say Y here; if you
1090 say Y here even though you have a coprocessor, the coprocessor will
1091 be used nevertheless. (This behavior can be changed with the kernel
1092 command line option "no387", which comes handy if your coprocessor
1093 is broken. Try "man bootparam" or see the documentation of your boot
1094 loader (lilo or loadlin) about how to pass options to the kernel at
1095 boot time.) This means that it is a good idea to say Y here if you
1096 intend to use this kernel on different machines.
1098 More information about the internals of the Linux math coprocessor
1099 emulation can be found in <file:arch/x86/math-emu/README>.
1101 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1102 kernel, it won't hurt.
1105 bool "MTRR (Memory Type Range Register) support"
1107 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1108 the Memory Type Range Registers (MTRRs) may be used to control
1109 processor access to memory ranges. This is most useful if you have
1110 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1111 allows bus write transfers to be combined into a larger transfer
1112 before bursting over the PCI/AGP bus. This can increase performance
1113 of image write operations 2.5 times or more. Saying Y here creates a
1114 /proc/mtrr file which may be used to manipulate your processor's
1115 MTRRs. Typically the X server should use this.
1117 This code has a reasonably generic interface so that similar
1118 control registers on other processors can be easily supported
1121 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1122 Registers (ARRs) which provide a similar functionality to MTRRs. For
1123 these, the ARRs are used to emulate the MTRRs.
1124 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1125 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1126 write-combining. All of these processors are supported by this code
1127 and it makes sense to say Y here if you have one of them.
1129 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1130 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1131 can lead to all sorts of problems, so it's good to say Y here.
1133 You can safely say Y even if your machine doesn't have MTRRs, you'll
1134 just add about 9 KB to your kernel.
1136 See <file:Documentation/mtrr.txt> for more information.
1138 config MTRR_SANITIZER
1140 prompt "MTRR cleanup support"
1143 Convert MTRR layout from continuous to discrete, so some X driver
1144 could add WB entries.
1146 Say N here if you see bootup problems (boot crash, boot hang,
1147 spontaneous reboots).
1149 Could be disabled with disable_mtrr_cleanup. Also mtrr_chunk_size
1150 could be used to send largest mtrr entry size for continuous block
1151 to hold holes (aka. UC entries)
1155 config MTRR_SANITIZER_ENABLE_DEFAULT
1156 int "MTRR cleanup enable value (0-1)"
1159 depends on MTRR_SANITIZER
1161 Enable mtrr cleanup default value
1163 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1164 int "MTRR cleanup spare reg num (0-7)"
1167 depends on MTRR_SANITIZER
1169 mtrr cleanup spare entries default, it can be changed via
1174 prompt "x86 PAT support"
1177 Use PAT attributes to setup page level cache control.
1179 PATs are the modern equivalents of MTRRs and are much more
1180 flexible than MTRRs.
1182 Say N here if you see bootup problems (boot crash, boot hang,
1183 spontaneous reboots) or a non-working video driver.
1189 prompt "EFI runtime service support"
1192 This enables the kernel to use EFI runtime services that are
1193 available (such as the EFI variable services).
1195 This option is only useful on systems that have EFI firmware.
1196 In addition, you should use the latest ELILO loader available
1197 at <http://elilo.sourceforge.net> in order to take advantage
1198 of EFI runtime services. However, even with this option, the
1199 resultant kernel should continue to boot on existing non-EFI
1204 prompt "Enable kernel irq balancing"
1205 depends on X86_32 && SMP && X86_IO_APIC
1207 The default yes will allow the kernel to do irq load balancing.
1208 Saying no will keep the kernel from doing irq load balancing.
1212 prompt "Enable seccomp to safely compute untrusted bytecode"
1215 This kernel feature is useful for number crunching applications
1216 that may need to compute untrusted bytecode during their
1217 execution. By using pipes or other transports made available to
1218 the process as file descriptors supporting the read/write
1219 syscalls, it's possible to isolate those applications in
1220 their own address space using seccomp. Once seccomp is
1221 enabled via /proc/<pid>/seccomp, it cannot be disabled
1222 and the task is only allowed to execute a few safe syscalls
1223 defined by each seccomp mode.
1225 If unsure, say Y. Only embedded should say N here.
1227 config CC_STACKPROTECTOR
1228 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1229 depends on X86_64 && EXPERIMENTAL && BROKEN
1231 This option turns on the -fstack-protector GCC feature. This
1232 feature puts, at the beginning of critical functions, a canary
1233 value on the stack just before the return address, and validates
1234 the value just before actually returning. Stack based buffer
1235 overflows (that need to overwrite this return address) now also
1236 overwrite the canary, which gets detected and the attack is then
1237 neutralized via a kernel panic.
1239 This feature requires gcc version 4.2 or above, or a distribution
1240 gcc with the feature backported. Older versions are automatically
1241 detected and for those versions, this configuration option is ignored.
1243 config CC_STACKPROTECTOR_ALL
1244 bool "Use stack-protector for all functions"
1245 depends on CC_STACKPROTECTOR
1247 Normally, GCC only inserts the canary value protection for
1248 functions that use large-ish on-stack buffers. By enabling
1249 this option, GCC will be asked to do this for ALL functions.
1251 source kernel/Kconfig.hz
1254 bool "kexec system call"
1255 depends on X86_BIOS_REBOOT
1257 kexec is a system call that implements the ability to shutdown your
1258 current kernel, and to start another kernel. It is like a reboot
1259 but it is independent of the system firmware. And like a reboot
1260 you can start any kernel with it, not just Linux.
1262 The name comes from the similarity to the exec system call.
1264 It is an ongoing process to be certain the hardware in a machine
1265 is properly shutdown, so do not be surprised if this code does not
1266 initially work for you. It may help to enable device hotplugging
1267 support. As of this writing the exact hardware interface is
1268 strongly in flux, so no good recommendation can be made.
1271 bool "kernel crash dumps (EXPERIMENTAL)"
1272 depends on EXPERIMENTAL
1273 depends on X86_64 || (X86_32 && HIGHMEM)
1275 Generate crash dump after being started by kexec.
1276 This should be normally only set in special crash dump kernels
1277 which are loaded in the main kernel with kexec-tools into
1278 a specially reserved region and then later executed after
1279 a crash by kdump/kexec. The crash dump kernel must be compiled
1280 to a memory address not used by the main kernel or BIOS using
1281 PHYSICAL_START, or it must be built as a relocatable image
1282 (CONFIG_RELOCATABLE=y).
1283 For more details see Documentation/kdump/kdump.txt
1285 config PHYSICAL_START
1286 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1287 default "0x1000000" if X86_NUMAQ
1288 default "0x200000" if X86_64
1291 This gives the physical address where the kernel is loaded.
1293 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1294 bzImage will decompress itself to above physical address and
1295 run from there. Otherwise, bzImage will run from the address where
1296 it has been loaded by the boot loader and will ignore above physical
1299 In normal kdump cases one does not have to set/change this option
1300 as now bzImage can be compiled as a completely relocatable image
1301 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1302 address. This option is mainly useful for the folks who don't want
1303 to use a bzImage for capturing the crash dump and want to use a
1304 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1305 to be specifically compiled to run from a specific memory area
1306 (normally a reserved region) and this option comes handy.
1308 So if you are using bzImage for capturing the crash dump, leave
1309 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1310 Otherwise if you plan to use vmlinux for capturing the crash dump
1311 change this value to start of the reserved region (Typically 16MB
1312 0x1000000). In other words, it can be set based on the "X" value as
1313 specified in the "crashkernel=YM@XM" command line boot parameter
1314 passed to the panic-ed kernel. Typically this parameter is set as
1315 crashkernel=64M@16M. Please take a look at
1316 Documentation/kdump/kdump.txt for more details about crash dumps.
1318 Usage of bzImage for capturing the crash dump is recommended as
1319 one does not have to build two kernels. Same kernel can be used
1320 as production kernel and capture kernel. Above option should have
1321 gone away after relocatable bzImage support is introduced. But it
1322 is present because there are users out there who continue to use
1323 vmlinux for dump capture. This option should go away down the
1326 Don't change this unless you know what you are doing.
1329 bool "Build a relocatable kernel (EXPERIMENTAL)"
1330 depends on EXPERIMENTAL
1332 This builds a kernel image that retains relocation information
1333 so it can be loaded someplace besides the default 1MB.
1334 The relocations tend to make the kernel binary about 10% larger,
1335 but are discarded at runtime.
1337 One use is for the kexec on panic case where the recovery kernel
1338 must live at a different physical address than the primary
1341 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1342 it has been loaded at and the compile time physical address
1343 (CONFIG_PHYSICAL_START) is ignored.
1345 config PHYSICAL_ALIGN
1347 prompt "Alignment value to which kernel should be aligned" if X86_32
1348 default "0x100000" if X86_32
1349 default "0x200000" if X86_64
1350 range 0x2000 0x400000
1352 This value puts the alignment restrictions on physical address
1353 where kernel is loaded and run from. Kernel is compiled for an
1354 address which meets above alignment restriction.
1356 If bootloader loads the kernel at a non-aligned address and
1357 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1358 address aligned to above value and run from there.
1360 If bootloader loads the kernel at a non-aligned address and
1361 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1362 load address and decompress itself to the address it has been
1363 compiled for and run from there. The address for which kernel is
1364 compiled already meets above alignment restrictions. Hence the
1365 end result is that kernel runs from a physical address meeting
1366 above alignment restrictions.
1368 Don't change this unless you know what you are doing.
1371 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1372 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1374 Say Y here to experiment with turning CPUs off and on, and to
1375 enable suspend on SMP systems. CPUs can be controlled through
1376 /sys/devices/system/cpu.
1377 Say N if you want to disable CPU hotplug and don't need to
1382 prompt "Compat VDSO support"
1383 depends on X86_32 || IA32_EMULATION
1385 Map the 32-bit VDSO to the predictable old-style address too.
1387 Say N here if you are running a sufficiently recent glibc
1388 version (2.3.3 or later), to remove the high-mapped
1389 VDSO mapping and to exclusively use the randomized VDSO.
1395 config ARCH_ENABLE_MEMORY_HOTPLUG
1397 depends on X86_64 || (X86_32 && HIGHMEM)
1399 config HAVE_ARCH_EARLY_PFN_TO_NID
1403 menu "Power management options"
1404 depends on !X86_VOYAGER
1406 config ARCH_HIBERNATION_HEADER
1408 depends on X86_64 && HIBERNATION
1410 source "kernel/power/Kconfig"
1412 source "drivers/acpi/Kconfig"
1417 depends on APM || APM_MODULE
1420 tristate "APM (Advanced Power Management) BIOS support"
1421 depends on X86_32 && PM_SLEEP && !X86_VISWS
1423 APM is a BIOS specification for saving power using several different
1424 techniques. This is mostly useful for battery powered laptops with
1425 APM compliant BIOSes. If you say Y here, the system time will be
1426 reset after a RESUME operation, the /proc/apm device will provide
1427 battery status information, and user-space programs will receive
1428 notification of APM "events" (e.g. battery status change).
1430 If you select "Y" here, you can disable actual use of the APM
1431 BIOS by passing the "apm=off" option to the kernel at boot time.
1433 Note that the APM support is almost completely disabled for
1434 machines with more than one CPU.
1436 In order to use APM, you will need supporting software. For location
1437 and more information, read <file:Documentation/power/pm.txt> and the
1438 Battery Powered Linux mini-HOWTO, available from
1439 <http://www.tldp.org/docs.html#howto>.
1441 This driver does not spin down disk drives (see the hdparm(8)
1442 manpage ("man 8 hdparm") for that), and it doesn't turn off
1443 VESA-compliant "green" monitors.
1445 This driver does not support the TI 4000M TravelMate and the ACER
1446 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1447 desktop machines also don't have compliant BIOSes, and this driver
1448 may cause those machines to panic during the boot phase.
1450 Generally, if you don't have a battery in your machine, there isn't
1451 much point in using this driver and you should say N. If you get
1452 random kernel OOPSes or reboots that don't seem to be related to
1453 anything, try disabling/enabling this option (or disabling/enabling
1456 Some other things you should try when experiencing seemingly random,
1459 1) make sure that you have enough swap space and that it is
1461 2) pass the "no-hlt" option to the kernel
1462 3) switch on floating point emulation in the kernel and pass
1463 the "no387" option to the kernel
1464 4) pass the "floppy=nodma" option to the kernel
1465 5) pass the "mem=4M" option to the kernel (thereby disabling
1466 all but the first 4 MB of RAM)
1467 6) make sure that the CPU is not over clocked.
1468 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1469 8) disable the cache from your BIOS settings
1470 9) install a fan for the video card or exchange video RAM
1471 10) install a better fan for the CPU
1472 11) exchange RAM chips
1473 12) exchange the motherboard.
1475 To compile this driver as a module, choose M here: the
1476 module will be called apm.
1480 config APM_IGNORE_USER_SUSPEND
1481 bool "Ignore USER SUSPEND"
1483 This option will ignore USER SUSPEND requests. On machines with a
1484 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1485 series notebooks, it is necessary to say Y because of a BIOS bug.
1487 config APM_DO_ENABLE
1488 bool "Enable PM at boot time"
1490 Enable APM features at boot time. From page 36 of the APM BIOS
1491 specification: "When disabled, the APM BIOS does not automatically
1492 power manage devices, enter the Standby State, enter the Suspend
1493 State, or take power saving steps in response to CPU Idle calls."
1494 This driver will make CPU Idle calls when Linux is idle (unless this
1495 feature is turned off -- see "Do CPU IDLE calls", below). This
1496 should always save battery power, but more complicated APM features
1497 will be dependent on your BIOS implementation. You may need to turn
1498 this option off if your computer hangs at boot time when using APM
1499 support, or if it beeps continuously instead of suspending. Turn
1500 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1501 T400CDT. This is off by default since most machines do fine without
1505 bool "Make CPU Idle calls when idle"
1507 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1508 On some machines, this can activate improved power savings, such as
1509 a slowed CPU clock rate, when the machine is idle. These idle calls
1510 are made after the idle loop has run for some length of time (e.g.,
1511 333 mS). On some machines, this will cause a hang at boot time or
1512 whenever the CPU becomes idle. (On machines with more than one CPU,
1513 this option does nothing.)
1515 config APM_DISPLAY_BLANK
1516 bool "Enable console blanking using APM"
1518 Enable console blanking using the APM. Some laptops can use this to
1519 turn off the LCD backlight when the screen blanker of the Linux
1520 virtual console blanks the screen. Note that this is only used by
1521 the virtual console screen blanker, and won't turn off the backlight
1522 when using the X Window system. This also doesn't have anything to
1523 do with your VESA-compliant power-saving monitor. Further, this
1524 option doesn't work for all laptops -- it might not turn off your
1525 backlight at all, or it might print a lot of errors to the console,
1526 especially if you are using gpm.
1528 config APM_ALLOW_INTS
1529 bool "Allow interrupts during APM BIOS calls"
1531 Normally we disable external interrupts while we are making calls to
1532 the APM BIOS as a measure to lessen the effects of a badly behaving
1533 BIOS implementation. The BIOS should reenable interrupts if it
1534 needs to. Unfortunately, some BIOSes do not -- especially those in
1535 many of the newer IBM Thinkpads. If you experience hangs when you
1536 suspend, try setting this to Y. Otherwise, say N.
1538 config APM_REAL_MODE_POWER_OFF
1539 bool "Use real mode APM BIOS call to power off"
1541 Use real mode APM BIOS calls to switch off the computer. This is
1542 a work-around for a number of buggy BIOSes. Switch this option on if
1543 your computer crashes instead of powering off properly.
1547 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1549 source "drivers/cpuidle/Kconfig"
1554 menu "Bus options (PCI etc.)"
1559 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1561 Find out whether you have a PCI motherboard. PCI is the name of a
1562 bus system, i.e. the way the CPU talks to the other stuff inside
1563 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1564 VESA. If you have PCI, say Y, otherwise N.
1567 prompt "PCI access mode"
1568 depends on X86_32 && PCI && !X86_VISWS
1571 On PCI systems, the BIOS can be used to detect the PCI devices and
1572 determine their configuration. However, some old PCI motherboards
1573 have BIOS bugs and may crash if this is done. Also, some embedded
1574 PCI-based systems don't have any BIOS at all. Linux can also try to
1575 detect the PCI hardware directly without using the BIOS.
1577 With this option, you can specify how Linux should detect the
1578 PCI devices. If you choose "BIOS", the BIOS will be used,
1579 if you choose "Direct", the BIOS won't be used, and if you
1580 choose "MMConfig", then PCI Express MMCONFIG will be used.
1581 If you choose "Any", the kernel will try MMCONFIG, then the
1582 direct access method and falls back to the BIOS if that doesn't
1583 work. If unsure, go with the default, which is "Any".
1588 config PCI_GOMMCONFIG
1605 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1607 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1610 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC) || X86_VISWS)
1614 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1618 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1625 bool "Support mmconfig PCI config space access"
1626 depends on X86_64 && PCI && ACPI
1629 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1630 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1632 DMA remapping (DMAR) devices support enables independent address
1633 translations for Direct Memory Access (DMA) from devices.
1634 These DMA remapping devices are reported via ACPI tables
1635 and include PCI device scope covered by these DMA
1640 prompt "Support for Graphics workaround"
1643 Current Graphics drivers tend to use physical address
1644 for DMA and avoid using DMA APIs. Setting this config
1645 option permits the IOMMU driver to set a unity map for
1646 all the OS-visible memory. Hence the driver can continue
1647 to use physical addresses for DMA.
1649 config DMAR_FLOPPY_WA
1653 Floppy disk drivers are know to bypass DMA API calls
1654 thereby failing to work when IOMMU is enabled. This
1655 workaround will setup a 1:1 mapping for the first
1656 16M to make floppy (an ISA device) work.
1658 source "drivers/pci/pcie/Kconfig"
1660 source "drivers/pci/Kconfig"
1662 # x86_64 have no ISA slots, but do have ISA-style DMA.
1670 depends on !(X86_VOYAGER || X86_VISWS)
1672 Find out whether you have ISA slots on your motherboard. ISA is the
1673 name of a bus system, i.e. the way the CPU talks to the other stuff
1674 inside your box. Other bus systems are PCI, EISA, MicroChannel
1675 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1676 newer boards don't support it. If you have ISA, say Y, otherwise N.
1682 The Extended Industry Standard Architecture (EISA) bus was
1683 developed as an open alternative to the IBM MicroChannel bus.
1685 The EISA bus provided some of the features of the IBM MicroChannel
1686 bus while maintaining backward compatibility with cards made for
1687 the older ISA bus. The EISA bus saw limited use between 1988 and
1688 1995 when it was made obsolete by the PCI bus.
1690 Say Y here if you are building a kernel for an EISA-based machine.
1694 source "drivers/eisa/Kconfig"
1697 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1698 default y if X86_VOYAGER
1700 MicroChannel Architecture is found in some IBM PS/2 machines and
1701 laptops. It is a bus system similar to PCI or ISA. See
1702 <file:Documentation/mca.txt> (and especially the web page given
1703 there) before attempting to build an MCA bus kernel.
1705 source "drivers/mca/Kconfig"
1708 tristate "NatSemi SCx200 support"
1709 depends on !X86_VOYAGER
1711 This provides basic support for National Semiconductor's
1712 (now AMD's) Geode processors. The driver probes for the
1713 PCI-IDs of several on-chip devices, so its a good dependency
1714 for other scx200_* drivers.
1716 If compiled as a module, the driver is named scx200.
1718 config SCx200HR_TIMER
1719 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1720 depends on SCx200 && GENERIC_TIME
1723 This driver provides a clocksource built upon the on-chip
1724 27MHz high-resolution timer. Its also a workaround for
1725 NSC Geode SC-1100's buggy TSC, which loses time when the
1726 processor goes idle (as is done by the scheduler). The
1727 other workaround is idle=poll boot option.
1729 config GEODE_MFGPT_TIMER
1731 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1732 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1734 This driver provides a clock event source based on the MFGPT
1735 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1736 MFGPTs have a better resolution and max interval than the
1737 generic PIT, and are suitable for use as high-res timers.
1740 bool "One Laptop Per Child support"
1743 Add support for detecting the unique features of the OLPC
1750 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1752 source "drivers/pcmcia/Kconfig"
1754 source "drivers/pci/hotplug/Kconfig"
1759 menu "Executable file formats / Emulations"
1761 source "fs/Kconfig.binfmt"
1763 config IA32_EMULATION
1764 bool "IA32 Emulation"
1766 select COMPAT_BINFMT_ELF
1768 Include code to run 32-bit programs under a 64-bit kernel. You should
1769 likely turn this on, unless you're 100% sure that you don't have any
1770 32-bit programs left.
1773 tristate "IA32 a.out support"
1774 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1776 Support old a.out binaries in the 32bit emulation.
1780 depends on IA32_EMULATION
1782 config COMPAT_FOR_U64_ALIGNMENT
1786 config SYSVIPC_COMPAT
1788 depends on X86_64 && COMPAT && SYSVIPC
1793 source "net/Kconfig"
1795 source "drivers/Kconfig"
1797 source "drivers/firmware/Kconfig"
1801 source "arch/x86/Kconfig.debug"
1803 source "security/Kconfig"
1805 source "crypto/Kconfig"
1807 source "arch/x86/kvm/Kconfig"
1809 source "lib/Kconfig"