2 mainmenu "Linux Kernel Configuration for x86"
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
21 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_KRETPROBES
26 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
27 select HAVE_ARCH_KGDB if !X86_VOYAGER
31 default "arch/x86/configs/i386_defconfig" if X86_32
32 default "arch/x86/configs/x86_64_defconfig" if X86_64
35 config GENERIC_LOCKBREAK
41 config GENERIC_CMOS_UPDATE
44 config CLOCKSOURCE_WATCHDOG
47 config GENERIC_CLOCKEVENTS
50 config GENERIC_CLOCKEVENTS_BROADCAST
52 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
54 config LOCKDEP_SUPPORT
57 config STACKTRACE_SUPPORT
60 config HAVE_LATENCYTOP_SUPPORT
63 config FAST_CMPXCHG_LOCAL
76 config GENERIC_ISA_DMA
86 config GENERIC_HWEIGHT
92 config ARCH_MAY_HAVE_PC_FDC
95 config RWSEM_GENERIC_SPINLOCK
98 config RWSEM_XCHGADD_ALGORITHM
101 config ARCH_HAS_ILOG2_U32
104 config ARCH_HAS_ILOG2_U64
107 config ARCH_HAS_CPU_IDLE_WAIT
110 config GENERIC_CALIBRATE_DELAY
113 config GENERIC_TIME_VSYSCALL
117 config ARCH_HAS_CPU_RELAX
120 config ARCH_HAS_CACHE_LINE_SIZE
123 config HAVE_SETUP_PER_CPU_AREA
124 def_bool X86_64 || (X86_SMP && !X86_VOYAGER)
126 config HAVE_CPUMASK_OF_CPU_MAP
129 config ARCH_HIBERNATION_POSSIBLE
131 depends on !SMP || !X86_VOYAGER
133 config ARCH_SUSPEND_POSSIBLE
135 depends on !X86_VOYAGER
141 config ARCH_POPULATES_NODE_MAP
148 config ARCH_SUPPORTS_AOUT
151 config ARCH_SUPPORTS_OPTIMIZED_INLINING
154 # Use the generic interrupt handling code in kernel/irq/:
155 config GENERIC_HARDIRQS
159 config GENERIC_IRQ_PROBE
163 config GENERIC_PENDING_IRQ
165 depends on GENERIC_HARDIRQS && SMP
170 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
175 depends on X86_32 && SMP
179 depends on X86_64 && SMP
184 depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || X86_64
187 config X86_BIOS_REBOOT
189 depends on !X86_VISWS && !X86_VOYAGER
192 config X86_TRAMPOLINE
194 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
199 source "init/Kconfig"
201 menu "Processor type and features"
203 source "kernel/time/Kconfig"
206 bool "Symmetric multi-processing support"
208 This enables support for systems with more than one CPU. If you have
209 a system with only one CPU, like most personal computers, say N. If
210 you have a system with more than one CPU, say Y.
212 If you say N here, the kernel will run on single and multiprocessor
213 machines, but will use only one CPU of a multiprocessor machine. If
214 you say Y here, the kernel will run on many, but not all,
215 singleprocessor machines. On a singleprocessor machine, the kernel
216 will run faster if you say N here.
218 Note that if you say Y here and choose architecture "586" or
219 "Pentium" under "Processor family", the kernel will not work on 486
220 architectures. Similarly, multiprocessor kernels for the "PPro"
221 architecture may not work on all Pentium based boards.
223 People using multiprocessor machines who say Y here should also say
224 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
225 Management" code will be disabled if you say Y here.
227 See also <file:Documentation/i386/IO-APIC.txt>,
228 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
229 <http://www.tldp.org/docs.html#howto>.
231 If you don't know what to do here, say N.
233 config X86_FIND_SMP_CONFIG
235 depends on X86_MPPARSE || X86_VOYAGER || X86_VISWS
241 bool "Enable MPS table"
242 depends on ((X86_32 && (X86_LOCAL_APIC && !X86_VISWS)) || X86_64)
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_32 && (X86_LOCAL_APIC && !X86_VISWS)) || X86_64)
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)
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)"
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
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"
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
439 config MEMTEST_BOOTPARAM
440 bool "Memtest boot parameter"
444 This option adds a kernel parameter 'memtest', which allows memtest
445 to be disabled at boot. If this option is selected, memtest
446 functionality can be disabled with memtest=0 on the kernel
447 command line. The purpose of this option is to allow a single
448 kernel image to be distributed with memtest built in, but not
451 If you are unsure how to answer this question, answer Y.
453 config MEMTEST_BOOTPARAM_VALUE
454 int "Memtest boot parameter default value (0-4)"
455 depends on MEMTEST_BOOTPARAM
459 This option sets the default value for the kernel parameter
460 'memtest', which allows memtest to be disabled at boot. If this
461 option is set to 0 (zero), the memtest kernel parameter will
462 default to 0, disabling memtest at bootup. If this option is
463 set to 4, the memtest kernel parameter will default to 4,
464 enabling memtest at bootup, and use that as pattern number.
466 If you are unsure how to answer this question, answer 0.
470 depends on X86_32 && ACPI && NUMA && X86_GENERICARCH
473 config HAVE_ARCH_PARSE_SRAT
477 config X86_SUMMIT_NUMA
479 depends on X86_32 && NUMA && X86_GENERICARCH
481 config X86_CYCLONE_TIMER
483 depends on X86_GENERICARCH
485 config ES7000_CLUSTERED_APIC
487 depends on SMP && X86_ES7000 && MPENTIUMIII
489 source "arch/x86/Kconfig.cpu"
493 prompt "HPET Timer Support" if X86_32
495 Use the IA-PC HPET (High Precision Event Timer) to manage
496 time in preference to the PIT and RTC, if a HPET is
498 HPET is the next generation timer replacing legacy 8254s.
499 The HPET provides a stable time base on SMP
500 systems, unlike the TSC, but it is more expensive to access,
501 as it is off-chip. You can find the HPET spec at
502 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
504 You can safely choose Y here. However, HPET will only be
505 activated if the platform and the BIOS support this feature.
506 Otherwise the 8254 will be used for timing services.
508 Choose N to continue using the legacy 8254 timer.
510 config HPET_EMULATE_RTC
512 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
514 # Mark as embedded because too many people got it wrong.
515 # The code disables itself when not needed.
518 bool "Enable DMI scanning" if EMBEDDED
520 Enabled scanning of DMI to identify machine quirks. Say Y
521 here unless you have verified that your setup is not
522 affected by entries in the DMI blacklist. Required by PNP
526 bool "GART IOMMU support" if EMBEDDED
530 depends on X86_64 && PCI
532 Support for full DMA access of devices with 32bit memory access only
533 on systems with more than 3GB. This is usually needed for USB,
534 sound, many IDE/SATA chipsets and some other devices.
535 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
536 based hardware IOMMU and a software bounce buffer based IOMMU used
537 on Intel systems and as fallback.
538 The code is only active when needed (enough memory and limited
539 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
543 bool "IBM Calgary IOMMU support"
545 depends on X86_64 && PCI && EXPERIMENTAL
547 Support for hardware IOMMUs in IBM's xSeries x366 and x460
548 systems. Needed to run systems with more than 3GB of memory
549 properly with 32-bit PCI devices that do not support DAC
550 (Double Address Cycle). Calgary also supports bus level
551 isolation, where all DMAs pass through the IOMMU. This
552 prevents them from going anywhere except their intended
553 destination. This catches hard-to-find kernel bugs and
554 mis-behaving drivers and devices that do not use the DMA-API
555 properly to set up their DMA buffers. The IOMMU can be
556 turned off at boot time with the iommu=off parameter.
557 Normally the kernel will make the right choice by itself.
560 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
562 prompt "Should Calgary be enabled by default?"
563 depends on CALGARY_IOMMU
565 Should Calgary be enabled by default? if you choose 'y', Calgary
566 will be used (if it exists). If you choose 'n', Calgary will not be
567 used even if it exists. If you choose 'n' and would like to use
568 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
571 # need this always selected by IOMMU for the VIA workaround
575 Support for software bounce buffers used on x86-64 systems
576 which don't have a hardware IOMMU (e.g. the current generation
577 of Intel's x86-64 CPUs). Using this PCI devices which can only
578 access 32-bits of memory can be used on systems with more than
579 3 GB of memory. If unsure, say Y.
582 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB)
585 int "Maximum number of CPUs (2-255)"
588 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
591 This allows you to specify the maximum number of CPUs which this
592 kernel will support. The maximum supported value is 255 and the
593 minimum value which makes sense is 2.
595 This is purely to save memory - each supported CPU adds
596 approximately eight kilobytes to the kernel image.
599 bool "SMT (Hyperthreading) scheduler support"
602 SMT scheduler support improves the CPU scheduler's decision making
603 when dealing with Intel Pentium 4 chips with HyperThreading at a
604 cost of slightly increased overhead in some places. If unsure say
609 prompt "Multi-core scheduler support"
612 Multi-core scheduler support improves the CPU scheduler's decision
613 making when dealing with multi-core CPU chips at a cost of slightly
614 increased overhead in some places. If unsure say N here.
616 source "kernel/Kconfig.preempt"
619 bool "Local APIC support on uniprocessors"
620 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
622 A local APIC (Advanced Programmable Interrupt Controller) is an
623 integrated interrupt controller in the CPU. If you have a single-CPU
624 system which has a processor with a local APIC, you can say Y here to
625 enable and use it. If you say Y here even though your machine doesn't
626 have a local APIC, then the kernel will still run with no slowdown at
627 all. The local APIC supports CPU-generated self-interrupts (timer,
628 performance counters), and the NMI watchdog which detects hard
632 bool "IO-APIC support on uniprocessors"
633 depends on X86_UP_APIC
635 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
636 SMP-capable replacement for PC-style interrupt controllers. Most
637 SMP systems and many recent uniprocessor systems have one.
639 If you have a single-CPU system with an IO-APIC, you can say Y here
640 to use it. If you say Y here even though your machine doesn't have
641 an IO-APIC, then the kernel will still run with no slowdown at all.
643 config X86_LOCAL_APIC
645 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
649 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
651 config X86_VISWS_APIC
653 depends on X86_32 && X86_VISWS
656 bool "Machine Check Exception"
657 depends on !X86_VOYAGER
659 Machine Check Exception support allows the processor to notify the
660 kernel if it detects a problem (e.g. overheating, component failure).
661 The action the kernel takes depends on the severity of the problem,
662 ranging from a warning message on the console, to halting the machine.
663 Your processor must be a Pentium or newer to support this - check the
664 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
665 have a design flaw which leads to false MCE events - hence MCE is
666 disabled on all P5 processors, unless explicitly enabled with "mce"
667 as a boot argument. Similarly, if MCE is built in and creates a
668 problem on some new non-standard machine, you can boot with "nomce"
669 to disable it. MCE support simply ignores non-MCE processors like
670 the 386 and 486, so nearly everyone can say Y here.
674 prompt "Intel MCE features"
675 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
677 Additional support for intel specific MCE features such as
682 prompt "AMD MCE features"
683 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
685 Additional support for AMD specific MCE features such as
686 the DRAM Error Threshold.
688 config X86_MCE_NONFATAL
689 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
690 depends on X86_32 && X86_MCE
692 Enabling this feature starts a timer that triggers every 5 seconds which
693 will look at the machine check registers to see if anything happened.
694 Non-fatal problems automatically get corrected (but still logged).
695 Disable this if you don't want to see these messages.
696 Seeing the messages this option prints out may be indicative of dying
697 or out-of-spec (ie, overclocked) hardware.
698 This option only does something on certain CPUs.
699 (AMD Athlon/Duron and Intel Pentium 4)
701 config X86_MCE_P4THERMAL
702 bool "check for P4 thermal throttling interrupt."
703 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
705 Enabling this feature will cause a message to be printed when the P4
706 enters thermal throttling.
709 bool "Enable VM86 support" if EMBEDDED
713 This option is required by programs like DOSEMU to run 16-bit legacy
714 code on X86 processors. It also may be needed by software like
715 XFree86 to initialize some video cards via BIOS. Disabling this
716 option saves about 6k.
719 tristate "Toshiba Laptop support"
722 This adds a driver to safely access the System Management Mode of
723 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
724 not work on models with a Phoenix BIOS. The System Management Mode
725 is used to set the BIOS and power saving options on Toshiba portables.
727 For information on utilities to make use of this driver see the
728 Toshiba Linux utilities web site at:
729 <http://www.buzzard.org.uk/toshiba/>.
731 Say Y if you intend to run this kernel on a Toshiba portable.
735 tristate "Dell laptop support"
737 This adds a driver to safely access the System Management Mode
738 of the CPU on the Dell Inspiron 8000. The System Management Mode
739 is used to read cpu temperature and cooling fan status and to
740 control the fans on the I8K portables.
742 This driver has been tested only on the Inspiron 8000 but it may
743 also work with other Dell laptops. You can force loading on other
744 models by passing the parameter `force=1' to the module. Use at
747 For information on utilities to make use of this driver see the
748 I8K Linux utilities web site at:
749 <http://people.debian.org/~dz/i8k/>
751 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
754 config X86_REBOOTFIXUPS
756 prompt "Enable X86 board specific fixups for reboot"
757 depends on X86_32 && X86
759 This enables chipset and/or board specific fixups to be done
760 in order to get reboot to work correctly. This is only needed on
761 some combinations of hardware and BIOS. The symptom, for which
762 this config is intended, is when reboot ends with a stalled/hung
765 Currently, the only fixup is for the Geode machines using
766 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
768 Say Y if you want to enable the fixup. Currently, it's safe to
769 enable this option even if you don't need it.
773 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
776 If you say Y here, you will be able to update the microcode on
777 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
778 Pentium III, Pentium 4, Xeon etc. You will obviously need the
779 actual microcode binary data itself which is not shipped with the
782 For latest news and information on obtaining all the required
783 ingredients for this driver, check:
784 <http://www.urbanmyth.org/microcode/>.
786 To compile this driver as a module, choose M here: the
787 module will be called microcode.
789 config MICROCODE_OLD_INTERFACE
794 tristate "/dev/cpu/*/msr - Model-specific register support"
796 This device gives privileged processes access to the x86
797 Model-Specific Registers (MSRs). It is a character device with
798 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
799 MSR accesses are directed to a specific CPU on multi-processor
803 tristate "/dev/cpu/*/cpuid - CPU information support"
805 This device gives processes access to the x86 CPUID instruction to
806 be executed on a specific processor. It is a character device
807 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
811 prompt "High Memory Support"
812 default HIGHMEM4G if !X86_NUMAQ
813 default HIGHMEM64G if X86_NUMAQ
818 depends on !X86_NUMAQ
820 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
821 However, the address space of 32-bit x86 processors is only 4
822 Gigabytes large. That means that, if you have a large amount of
823 physical memory, not all of it can be "permanently mapped" by the
824 kernel. The physical memory that's not permanently mapped is called
827 If you are compiling a kernel which will never run on a machine with
828 more than 1 Gigabyte total physical RAM, answer "off" here (default
829 choice and suitable for most users). This will result in a "3GB/1GB"
830 split: 3GB are mapped so that each process sees a 3GB virtual memory
831 space and the remaining part of the 4GB virtual memory space is used
832 by the kernel to permanently map as much physical memory as
835 If the machine has between 1 and 4 Gigabytes physical RAM, then
838 If more than 4 Gigabytes is used then answer "64GB" here. This
839 selection turns Intel PAE (Physical Address Extension) mode on.
840 PAE implements 3-level paging on IA32 processors. PAE is fully
841 supported by Linux, PAE mode is implemented on all recent Intel
842 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
843 then the kernel will not boot on CPUs that don't support PAE!
845 The actual amount of total physical memory will either be
846 auto detected or can be forced by using a kernel command line option
847 such as "mem=256M". (Try "man bootparam" or see the documentation of
848 your boot loader (lilo or loadlin) about how to pass options to the
849 kernel at boot time.)
851 If unsure, say "off".
855 depends on !X86_NUMAQ
857 Select this if you have a 32-bit processor and between 1 and 4
858 gigabytes of physical RAM.
862 depends on !M386 && !M486
865 Select this if you have a 32-bit processor and more than 4
866 gigabytes of physical RAM.
871 depends on EXPERIMENTAL
872 prompt "Memory split" if EMBEDDED
876 Select the desired split between kernel and user memory.
878 If the address range available to the kernel is less than the
879 physical memory installed, the remaining memory will be available
880 as "high memory". Accessing high memory is a little more costly
881 than low memory, as it needs to be mapped into the kernel first.
882 Note that increasing the kernel address space limits the range
883 available to user programs, making the address space there
884 tighter. Selecting anything other than the default 3G/1G split
885 will also likely make your kernel incompatible with binary-only
888 If you are not absolutely sure what you are doing, leave this
892 bool "3G/1G user/kernel split"
893 config VMSPLIT_3G_OPT
895 bool "3G/1G user/kernel split (for full 1G low memory)"
897 bool "2G/2G user/kernel split"
898 config VMSPLIT_2G_OPT
900 bool "2G/2G user/kernel split (for full 2G low memory)"
902 bool "1G/3G user/kernel split"
907 default 0xB0000000 if VMSPLIT_3G_OPT
908 default 0x80000000 if VMSPLIT_2G
909 default 0x78000000 if VMSPLIT_2G_OPT
910 default 0x40000000 if VMSPLIT_1G
916 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
920 prompt "PAE (Physical Address Extension) Support"
921 depends on X86_32 && !HIGHMEM4G
922 select RESOURCES_64BIT
924 PAE is required for NX support, and furthermore enables
925 larger swapspace support for non-overcommit purposes. It
926 has the cost of more pagetable lookup overhead, and also
927 consumes more pagetable space per process.
929 # Common NUMA Features
931 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
933 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
935 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
937 Enable NUMA (Non Uniform Memory Access) support.
938 The kernel will try to allocate memory used by a CPU on the
939 local memory controller of the CPU and add some more
940 NUMA awareness to the kernel.
942 For i386 this is currently highly experimental and should be only
943 used for kernel development. It might also cause boot failures.
944 For x86_64 this is recommended on all multiprocessor Opteron systems.
945 If the system is EM64T, you should say N unless your system is
948 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
949 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
953 prompt "Old style AMD Opteron NUMA detection"
954 depends on X86_64 && NUMA && PCI
956 Enable K8 NUMA node topology detection. You should say Y here if
957 you have a multi processor AMD K8 system. This uses an old
958 method to read the NUMA configuration directly from the builtin
959 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
960 instead, which also takes priority if both are compiled in.
962 config X86_64_ACPI_NUMA
964 prompt "ACPI NUMA detection"
965 depends on X86_64 && NUMA && ACPI && PCI
968 Enable ACPI SRAT based node topology detection.
970 # Some NUMA nodes have memory ranges that span
971 # other nodes. Even though a pfn is valid and
972 # between a node's start and end pfns, it may not
973 # reside on that node. See memmap_init_zone()
975 config NODES_SPAN_OTHER_NODES
977 depends on X86_64_ACPI_NUMA
980 bool "NUMA emulation"
981 depends on X86_64 && NUMA
983 Enable NUMA emulation. A flat machine will be split
984 into virtual nodes when booted with "numa=fake=N", where N is the
985 number of nodes. This is only useful for debugging.
988 int "Max num nodes shift(1-9)"
990 default "6" if X86_64
991 default "4" if X86_NUMAQ
993 depends on NEED_MULTIPLE_NODES
995 config HAVE_ARCH_BOOTMEM_NODE
997 depends on X86_32 && NUMA
999 config ARCH_HAVE_MEMORY_PRESENT
1001 depends on X86_32 && DISCONTIGMEM
1003 config NEED_NODE_MEMMAP_SIZE
1005 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1007 config HAVE_ARCH_ALLOC_REMAP
1009 depends on X86_32 && NUMA
1011 config ARCH_FLATMEM_ENABLE
1013 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
1015 config ARCH_DISCONTIGMEM_ENABLE
1017 depends on NUMA && X86_32
1019 config ARCH_DISCONTIGMEM_DEFAULT
1021 depends on NUMA && X86_32
1023 config ARCH_SPARSEMEM_DEFAULT
1027 config ARCH_SPARSEMEM_ENABLE
1029 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1030 select SPARSEMEM_STATIC if X86_32
1031 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1033 config ARCH_SELECT_MEMORY_MODEL
1035 depends on ARCH_SPARSEMEM_ENABLE
1037 config ARCH_MEMORY_PROBE
1039 depends on MEMORY_HOTPLUG
1044 bool "Allocate 3rd-level pagetables from highmem"
1045 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1047 The VM uses one page table entry for each page of physical memory.
1048 For systems with a lot of RAM, this can be wasteful of precious
1049 low memory. Setting this option will put user-space page table
1050 entries in high memory.
1052 config MATH_EMULATION
1054 prompt "Math emulation" if X86_32
1056 Linux can emulate a math coprocessor (used for floating point
1057 operations) if you don't have one. 486DX and Pentium processors have
1058 a math coprocessor built in, 486SX and 386 do not, unless you added
1059 a 487DX or 387, respectively. (The messages during boot time can
1060 give you some hints here ["man dmesg"].) Everyone needs either a
1061 coprocessor or this emulation.
1063 If you don't have a math coprocessor, you need to say Y here; if you
1064 say Y here even though you have a coprocessor, the coprocessor will
1065 be used nevertheless. (This behavior can be changed with the kernel
1066 command line option "no387", which comes handy if your coprocessor
1067 is broken. Try "man bootparam" or see the documentation of your boot
1068 loader (lilo or loadlin) about how to pass options to the kernel at
1069 boot time.) This means that it is a good idea to say Y here if you
1070 intend to use this kernel on different machines.
1072 More information about the internals of the Linux math coprocessor
1073 emulation can be found in <file:arch/x86/math-emu/README>.
1075 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1076 kernel, it won't hurt.
1079 bool "MTRR (Memory Type Range Register) support"
1081 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1082 the Memory Type Range Registers (MTRRs) may be used to control
1083 processor access to memory ranges. This is most useful if you have
1084 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1085 allows bus write transfers to be combined into a larger transfer
1086 before bursting over the PCI/AGP bus. This can increase performance
1087 of image write operations 2.5 times or more. Saying Y here creates a
1088 /proc/mtrr file which may be used to manipulate your processor's
1089 MTRRs. Typically the X server should use this.
1091 This code has a reasonably generic interface so that similar
1092 control registers on other processors can be easily supported
1095 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1096 Registers (ARRs) which provide a similar functionality to MTRRs. For
1097 these, the ARRs are used to emulate the MTRRs.
1098 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1099 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1100 write-combining. All of these processors are supported by this code
1101 and it makes sense to say Y here if you have one of them.
1103 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1104 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1105 can lead to all sorts of problems, so it's good to say Y here.
1107 You can safely say Y even if your machine doesn't have MTRRs, you'll
1108 just add about 9 KB to your kernel.
1110 See <file:Documentation/mtrr.txt> for more information.
1112 config MTRR_SANITIZER
1114 prompt "MTRR cleanup support"
1117 Convert MTRR layout from continuous to discrete, so some X driver
1118 could add WB entries.
1120 Say N here if you see bootup problems (boot crash, boot hang,
1121 spontaneous reboots).
1123 Could be disabled with disable_mtrr_cleanup. Also mtrr_chunk_size
1124 could be used to send largest mtrr entry size for continuous block
1125 to hold holes (aka. UC entries)
1129 config MTRR_SANITIZER_ENABLE_DEFAULT
1130 int "MTRR cleanup enable value (0-1)"
1133 depends on MTRR_SANITIZER
1135 Enable mtrr cleanup default value
1137 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1138 int "MTRR cleanup spare reg num (0-7)"
1141 depends on MTRR_SANITIZER
1143 mtrr cleanup spare entries default, it can be changed via
1148 prompt "x86 PAT support"
1151 Use PAT attributes to setup page level cache control.
1153 PATs are the modern equivalents of MTRRs and are much more
1154 flexible than MTRRs.
1156 Say N here if you see bootup problems (boot crash, boot hang,
1157 spontaneous reboots) or a non-working video driver.
1163 prompt "EFI runtime service support"
1166 This enables the kernel to use EFI runtime services that are
1167 available (such as the EFI variable services).
1169 This option is only useful on systems that have EFI firmware.
1170 In addition, you should use the latest ELILO loader available
1171 at <http://elilo.sourceforge.net> in order to take advantage
1172 of EFI runtime services. However, even with this option, the
1173 resultant kernel should continue to boot on existing non-EFI
1178 prompt "Enable kernel irq balancing"
1179 depends on X86_32 && SMP && X86_IO_APIC
1181 The default yes will allow the kernel to do irq load balancing.
1182 Saying no will keep the kernel from doing irq load balancing.
1186 prompt "Enable seccomp to safely compute untrusted bytecode"
1189 This kernel feature is useful for number crunching applications
1190 that may need to compute untrusted bytecode during their
1191 execution. By using pipes or other transports made available to
1192 the process as file descriptors supporting the read/write
1193 syscalls, it's possible to isolate those applications in
1194 their own address space using seccomp. Once seccomp is
1195 enabled via /proc/<pid>/seccomp, it cannot be disabled
1196 and the task is only allowed to execute a few safe syscalls
1197 defined by each seccomp mode.
1199 If unsure, say Y. Only embedded should say N here.
1201 config CC_STACKPROTECTOR
1202 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1203 depends on X86_64 && EXPERIMENTAL && BROKEN
1205 This option turns on the -fstack-protector GCC feature. This
1206 feature puts, at the beginning of critical functions, a canary
1207 value on the stack just before the return address, and validates
1208 the value just before actually returning. Stack based buffer
1209 overflows (that need to overwrite this return address) now also
1210 overwrite the canary, which gets detected and the attack is then
1211 neutralized via a kernel panic.
1213 This feature requires gcc version 4.2 or above, or a distribution
1214 gcc with the feature backported. Older versions are automatically
1215 detected and for those versions, this configuration option is ignored.
1217 config CC_STACKPROTECTOR_ALL
1218 bool "Use stack-protector for all functions"
1219 depends on CC_STACKPROTECTOR
1221 Normally, GCC only inserts the canary value protection for
1222 functions that use large-ish on-stack buffers. By enabling
1223 this option, GCC will be asked to do this for ALL functions.
1225 source kernel/Kconfig.hz
1228 bool "kexec system call"
1229 depends on X86_BIOS_REBOOT
1231 kexec is a system call that implements the ability to shutdown your
1232 current kernel, and to start another kernel. It is like a reboot
1233 but it is independent of the system firmware. And like a reboot
1234 you can start any kernel with it, not just Linux.
1236 The name comes from the similarity to the exec system call.
1238 It is an ongoing process to be certain the hardware in a machine
1239 is properly shutdown, so do not be surprised if this code does not
1240 initially work for you. It may help to enable device hotplugging
1241 support. As of this writing the exact hardware interface is
1242 strongly in flux, so no good recommendation can be made.
1245 bool "kernel crash dumps (EXPERIMENTAL)"
1246 depends on EXPERIMENTAL
1247 depends on X86_64 || (X86_32 && HIGHMEM)
1249 Generate crash dump after being started by kexec.
1250 This should be normally only set in special crash dump kernels
1251 which are loaded in the main kernel with kexec-tools into
1252 a specially reserved region and then later executed after
1253 a crash by kdump/kexec. The crash dump kernel must be compiled
1254 to a memory address not used by the main kernel or BIOS using
1255 PHYSICAL_START, or it must be built as a relocatable image
1256 (CONFIG_RELOCATABLE=y).
1257 For more details see Documentation/kdump/kdump.txt
1259 config PHYSICAL_START
1260 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1261 default "0x1000000" if X86_NUMAQ
1262 default "0x200000" if X86_64
1265 This gives the physical address where the kernel is loaded.
1267 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1268 bzImage will decompress itself to above physical address and
1269 run from there. Otherwise, bzImage will run from the address where
1270 it has been loaded by the boot loader and will ignore above physical
1273 In normal kdump cases one does not have to set/change this option
1274 as now bzImage can be compiled as a completely relocatable image
1275 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1276 address. This option is mainly useful for the folks who don't want
1277 to use a bzImage for capturing the crash dump and want to use a
1278 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1279 to be specifically compiled to run from a specific memory area
1280 (normally a reserved region) and this option comes handy.
1282 So if you are using bzImage for capturing the crash dump, leave
1283 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1284 Otherwise if you plan to use vmlinux for capturing the crash dump
1285 change this value to start of the reserved region (Typically 16MB
1286 0x1000000). In other words, it can be set based on the "X" value as
1287 specified in the "crashkernel=YM@XM" command line boot parameter
1288 passed to the panic-ed kernel. Typically this parameter is set as
1289 crashkernel=64M@16M. Please take a look at
1290 Documentation/kdump/kdump.txt for more details about crash dumps.
1292 Usage of bzImage for capturing the crash dump is recommended as
1293 one does not have to build two kernels. Same kernel can be used
1294 as production kernel and capture kernel. Above option should have
1295 gone away after relocatable bzImage support is introduced. But it
1296 is present because there are users out there who continue to use
1297 vmlinux for dump capture. This option should go away down the
1300 Don't change this unless you know what you are doing.
1303 bool "Build a relocatable kernel (EXPERIMENTAL)"
1304 depends on EXPERIMENTAL
1306 This builds a kernel image that retains relocation information
1307 so it can be loaded someplace besides the default 1MB.
1308 The relocations tend to make the kernel binary about 10% larger,
1309 but are discarded at runtime.
1311 One use is for the kexec on panic case where the recovery kernel
1312 must live at a different physical address than the primary
1315 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1316 it has been loaded at and the compile time physical address
1317 (CONFIG_PHYSICAL_START) is ignored.
1319 config PHYSICAL_ALIGN
1321 prompt "Alignment value to which kernel should be aligned" if X86_32
1322 default "0x100000" if X86_32
1323 default "0x200000" if X86_64
1324 range 0x2000 0x400000
1326 This value puts the alignment restrictions on physical address
1327 where kernel is loaded and run from. Kernel is compiled for an
1328 address which meets above alignment restriction.
1330 If bootloader loads the kernel at a non-aligned address and
1331 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1332 address aligned to above value and run from there.
1334 If bootloader loads the kernel at a non-aligned address and
1335 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1336 load address and decompress itself to the address it has been
1337 compiled for and run from there. The address for which kernel is
1338 compiled already meets above alignment restrictions. Hence the
1339 end result is that kernel runs from a physical address meeting
1340 above alignment restrictions.
1342 Don't change this unless you know what you are doing.
1345 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1346 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1348 Say Y here to experiment with turning CPUs off and on, and to
1349 enable suspend on SMP systems. CPUs can be controlled through
1350 /sys/devices/system/cpu.
1351 Say N if you want to disable CPU hotplug and don't need to
1356 prompt "Compat VDSO support"
1357 depends on X86_32 || IA32_EMULATION
1359 Map the 32-bit VDSO to the predictable old-style address too.
1361 Say N here if you are running a sufficiently recent glibc
1362 version (2.3.3 or later), to remove the high-mapped
1363 VDSO mapping and to exclusively use the randomized VDSO.
1369 config ARCH_ENABLE_MEMORY_HOTPLUG
1371 depends on X86_64 || (X86_32 && HIGHMEM)
1373 config HAVE_ARCH_EARLY_PFN_TO_NID
1377 menu "Power management options"
1378 depends on !X86_VOYAGER
1380 config ARCH_HIBERNATION_HEADER
1382 depends on X86_64 && HIBERNATION
1384 source "kernel/power/Kconfig"
1386 source "drivers/acpi/Kconfig"
1391 depends on APM || APM_MODULE
1394 tristate "APM (Advanced Power Management) BIOS support"
1395 depends on X86_32 && PM_SLEEP && !X86_VISWS
1397 APM is a BIOS specification for saving power using several different
1398 techniques. This is mostly useful for battery powered laptops with
1399 APM compliant BIOSes. If you say Y here, the system time will be
1400 reset after a RESUME operation, the /proc/apm device will provide
1401 battery status information, and user-space programs will receive
1402 notification of APM "events" (e.g. battery status change).
1404 If you select "Y" here, you can disable actual use of the APM
1405 BIOS by passing the "apm=off" option to the kernel at boot time.
1407 Note that the APM support is almost completely disabled for
1408 machines with more than one CPU.
1410 In order to use APM, you will need supporting software. For location
1411 and more information, read <file:Documentation/power/pm.txt> and the
1412 Battery Powered Linux mini-HOWTO, available from
1413 <http://www.tldp.org/docs.html#howto>.
1415 This driver does not spin down disk drives (see the hdparm(8)
1416 manpage ("man 8 hdparm") for that), and it doesn't turn off
1417 VESA-compliant "green" monitors.
1419 This driver does not support the TI 4000M TravelMate and the ACER
1420 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1421 desktop machines also don't have compliant BIOSes, and this driver
1422 may cause those machines to panic during the boot phase.
1424 Generally, if you don't have a battery in your machine, there isn't
1425 much point in using this driver and you should say N. If you get
1426 random kernel OOPSes or reboots that don't seem to be related to
1427 anything, try disabling/enabling this option (or disabling/enabling
1430 Some other things you should try when experiencing seemingly random,
1433 1) make sure that you have enough swap space and that it is
1435 2) pass the "no-hlt" option to the kernel
1436 3) switch on floating point emulation in the kernel and pass
1437 the "no387" option to the kernel
1438 4) pass the "floppy=nodma" option to the kernel
1439 5) pass the "mem=4M" option to the kernel (thereby disabling
1440 all but the first 4 MB of RAM)
1441 6) make sure that the CPU is not over clocked.
1442 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1443 8) disable the cache from your BIOS settings
1444 9) install a fan for the video card or exchange video RAM
1445 10) install a better fan for the CPU
1446 11) exchange RAM chips
1447 12) exchange the motherboard.
1449 To compile this driver as a module, choose M here: the
1450 module will be called apm.
1454 config APM_IGNORE_USER_SUSPEND
1455 bool "Ignore USER SUSPEND"
1457 This option will ignore USER SUSPEND requests. On machines with a
1458 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1459 series notebooks, it is necessary to say Y because of a BIOS bug.
1461 config APM_DO_ENABLE
1462 bool "Enable PM at boot time"
1464 Enable APM features at boot time. From page 36 of the APM BIOS
1465 specification: "When disabled, the APM BIOS does not automatically
1466 power manage devices, enter the Standby State, enter the Suspend
1467 State, or take power saving steps in response to CPU Idle calls."
1468 This driver will make CPU Idle calls when Linux is idle (unless this
1469 feature is turned off -- see "Do CPU IDLE calls", below). This
1470 should always save battery power, but more complicated APM features
1471 will be dependent on your BIOS implementation. You may need to turn
1472 this option off if your computer hangs at boot time when using APM
1473 support, or if it beeps continuously instead of suspending. Turn
1474 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1475 T400CDT. This is off by default since most machines do fine without
1479 bool "Make CPU Idle calls when idle"
1481 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1482 On some machines, this can activate improved power savings, such as
1483 a slowed CPU clock rate, when the machine is idle. These idle calls
1484 are made after the idle loop has run for some length of time (e.g.,
1485 333 mS). On some machines, this will cause a hang at boot time or
1486 whenever the CPU becomes idle. (On machines with more than one CPU,
1487 this option does nothing.)
1489 config APM_DISPLAY_BLANK
1490 bool "Enable console blanking using APM"
1492 Enable console blanking using the APM. Some laptops can use this to
1493 turn off the LCD backlight when the screen blanker of the Linux
1494 virtual console blanks the screen. Note that this is only used by
1495 the virtual console screen blanker, and won't turn off the backlight
1496 when using the X Window system. This also doesn't have anything to
1497 do with your VESA-compliant power-saving monitor. Further, this
1498 option doesn't work for all laptops -- it might not turn off your
1499 backlight at all, or it might print a lot of errors to the console,
1500 especially if you are using gpm.
1502 config APM_ALLOW_INTS
1503 bool "Allow interrupts during APM BIOS calls"
1505 Normally we disable external interrupts while we are making calls to
1506 the APM BIOS as a measure to lessen the effects of a badly behaving
1507 BIOS implementation. The BIOS should reenable interrupts if it
1508 needs to. Unfortunately, some BIOSes do not -- especially those in
1509 many of the newer IBM Thinkpads. If you experience hangs when you
1510 suspend, try setting this to Y. Otherwise, say N.
1512 config APM_REAL_MODE_POWER_OFF
1513 bool "Use real mode APM BIOS call to power off"
1515 Use real mode APM BIOS calls to switch off the computer. This is
1516 a work-around for a number of buggy BIOSes. Switch this option on if
1517 your computer crashes instead of powering off properly.
1521 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1523 source "drivers/cpuidle/Kconfig"
1528 menu "Bus options (PCI etc.)"
1531 bool "PCI support" if !X86_VISWS && !X86_VSMP
1532 depends on !X86_VOYAGER
1534 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1536 Find out whether you have a PCI motherboard. PCI is the name of a
1537 bus system, i.e. the way the CPU talks to the other stuff inside
1538 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1539 VESA. If you have PCI, say Y, otherwise N.
1542 prompt "PCI access mode"
1543 depends on X86_32 && PCI && !X86_VISWS
1546 On PCI systems, the BIOS can be used to detect the PCI devices and
1547 determine their configuration. However, some old PCI motherboards
1548 have BIOS bugs and may crash if this is done. Also, some embedded
1549 PCI-based systems don't have any BIOS at all. Linux can also try to
1550 detect the PCI hardware directly without using the BIOS.
1552 With this option, you can specify how Linux should detect the
1553 PCI devices. If you choose "BIOS", the BIOS will be used,
1554 if you choose "Direct", the BIOS won't be used, and if you
1555 choose "MMConfig", then PCI Express MMCONFIG will be used.
1556 If you choose "Any", the kernel will try MMCONFIG, then the
1557 direct access method and falls back to the BIOS if that doesn't
1558 work. If unsure, go with the default, which is "Any".
1563 config PCI_GOMMCONFIG
1580 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1582 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1585 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC) || X86_VISWS)
1589 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1593 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1600 bool "Support mmconfig PCI config space access"
1601 depends on X86_64 && PCI && ACPI
1604 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1605 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1607 DMA remapping (DMAR) devices support enables independent address
1608 translations for Direct Memory Access (DMA) from devices.
1609 These DMA remapping devices are reported via ACPI tables
1610 and include PCI device scope covered by these DMA
1615 prompt "Support for Graphics workaround"
1618 Current Graphics drivers tend to use physical address
1619 for DMA and avoid using DMA APIs. Setting this config
1620 option permits the IOMMU driver to set a unity map for
1621 all the OS-visible memory. Hence the driver can continue
1622 to use physical addresses for DMA.
1624 config DMAR_FLOPPY_WA
1628 Floppy disk drivers are know to bypass DMA API calls
1629 thereby failing to work when IOMMU is enabled. This
1630 workaround will setup a 1:1 mapping for the first
1631 16M to make floppy (an ISA device) work.
1633 source "drivers/pci/pcie/Kconfig"
1635 source "drivers/pci/Kconfig"
1637 # x86_64 have no ISA slots, but do have ISA-style DMA.
1645 depends on !(X86_VOYAGER || X86_VISWS)
1647 Find out whether you have ISA slots on your motherboard. ISA is the
1648 name of a bus system, i.e. the way the CPU talks to the other stuff
1649 inside your box. Other bus systems are PCI, EISA, MicroChannel
1650 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1651 newer boards don't support it. If you have ISA, say Y, otherwise N.
1657 The Extended Industry Standard Architecture (EISA) bus was
1658 developed as an open alternative to the IBM MicroChannel bus.
1660 The EISA bus provided some of the features of the IBM MicroChannel
1661 bus while maintaining backward compatibility with cards made for
1662 the older ISA bus. The EISA bus saw limited use between 1988 and
1663 1995 when it was made obsolete by the PCI bus.
1665 Say Y here if you are building a kernel for an EISA-based machine.
1669 source "drivers/eisa/Kconfig"
1672 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1673 default y if X86_VOYAGER
1675 MicroChannel Architecture is found in some IBM PS/2 machines and
1676 laptops. It is a bus system similar to PCI or ISA. See
1677 <file:Documentation/mca.txt> (and especially the web page given
1678 there) before attempting to build an MCA bus kernel.
1680 source "drivers/mca/Kconfig"
1683 tristate "NatSemi SCx200 support"
1684 depends on !X86_VOYAGER
1686 This provides basic support for National Semiconductor's
1687 (now AMD's) Geode processors. The driver probes for the
1688 PCI-IDs of several on-chip devices, so its a good dependency
1689 for other scx200_* drivers.
1691 If compiled as a module, the driver is named scx200.
1693 config SCx200HR_TIMER
1694 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1695 depends on SCx200 && GENERIC_TIME
1698 This driver provides a clocksource built upon the on-chip
1699 27MHz high-resolution timer. Its also a workaround for
1700 NSC Geode SC-1100's buggy TSC, which loses time when the
1701 processor goes idle (as is done by the scheduler). The
1702 other workaround is idle=poll boot option.
1704 config GEODE_MFGPT_TIMER
1706 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1707 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1709 This driver provides a clock event source based on the MFGPT
1710 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1711 MFGPTs have a better resolution and max interval than the
1712 generic PIT, and are suitable for use as high-res timers.
1715 bool "One Laptop Per Child support"
1718 Add support for detecting the unique features of the OLPC
1725 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1727 source "drivers/pcmcia/Kconfig"
1729 source "drivers/pci/hotplug/Kconfig"
1734 menu "Executable file formats / Emulations"
1736 source "fs/Kconfig.binfmt"
1738 config IA32_EMULATION
1739 bool "IA32 Emulation"
1741 select COMPAT_BINFMT_ELF
1743 Include code to run 32-bit programs under a 64-bit kernel. You should
1744 likely turn this on, unless you're 100% sure that you don't have any
1745 32-bit programs left.
1748 tristate "IA32 a.out support"
1749 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1751 Support old a.out binaries in the 32bit emulation.
1755 depends on IA32_EMULATION
1757 config COMPAT_FOR_U64_ALIGNMENT
1761 config SYSVIPC_COMPAT
1763 depends on X86_64 && COMPAT && SYSVIPC
1768 source "net/Kconfig"
1770 source "drivers/Kconfig"
1772 source "drivers/firmware/Kconfig"
1776 source "arch/x86/Kconfig.debug"
1778 source "security/Kconfig"
1780 source "crypto/Kconfig"
1782 source "arch/x86/kvm/Kconfig"
1784 source "lib/Kconfig"
projects / deliverable / linux.git / blob