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
24 select HAVE_KRETPROBES
25 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
28 config GENERIC_LOCKBREAK
34 config GENERIC_CMOS_UPDATE
37 config CLOCKSOURCE_WATCHDOG
40 config GENERIC_CLOCKEVENTS
43 config GENERIC_CLOCKEVENTS_BROADCAST
45 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
47 config LOCKDEP_SUPPORT
50 config STACKTRACE_SUPPORT
53 config HAVE_LATENCYTOP_SUPPORT
56 config SEMAPHORE_SLEEPERS
59 config FAST_CMPXCHG_LOCAL
72 config GENERIC_ISA_DMA
82 config GENERIC_HWEIGHT
88 config ARCH_MAY_HAVE_PC_FDC
94 config RWSEM_GENERIC_SPINLOCK
97 config RWSEM_XCHGADD_ALGORITHM
100 config ARCH_HAS_ILOG2_U32
103 config ARCH_HAS_ILOG2_U64
106 config ARCH_HAS_CPU_IDLE_WAIT
109 config GENERIC_CALIBRATE_DELAY
112 config GENERIC_TIME_VSYSCALL
116 config ARCH_HAS_CPU_RELAX
119 config HAVE_SETUP_PER_CPU_AREA
120 def_bool X86_64 || (X86_SMP && !X86_VOYAGER)
122 config ARCH_HIBERNATION_POSSIBLE
124 depends on !SMP || !X86_VOYAGER
126 config ARCH_SUSPEND_POSSIBLE
128 depends on !X86_VOYAGER
134 config ARCH_POPULATES_NODE_MAP
141 config ARCH_SUPPORTS_AOUT
144 # Use the generic interrupt handling code in kernel/irq/:
145 config GENERIC_HARDIRQS
149 config GENERIC_IRQ_PROBE
153 config GENERIC_PENDING_IRQ
155 depends on GENERIC_HARDIRQS && SMP
160 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
165 depends on X86_32 && SMP
169 depends on X86_64 && SMP
174 depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || X86_64
177 config X86_BIOS_REBOOT
179 depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
182 config X86_TRAMPOLINE
184 depends on X86_SMP || (X86_VOYAGER && SMP)
189 source "init/Kconfig"
191 menu "Processor type and features"
193 source "kernel/time/Kconfig"
196 bool "Symmetric multi-processing support"
198 This enables support for systems with more than one CPU. If you have
199 a system with only one CPU, like most personal computers, say N. If
200 you have a system with more than one CPU, say Y.
202 If you say N here, the kernel will run on single and multiprocessor
203 machines, but will use only one CPU of a multiprocessor machine. If
204 you say Y here, the kernel will run on many, but not all,
205 singleprocessor machines. On a singleprocessor machine, the kernel
206 will run faster if you say N here.
208 Note that if you say Y here and choose architecture "586" or
209 "Pentium" under "Processor family", the kernel will not work on 486
210 architectures. Similarly, multiprocessor kernels for the "PPro"
211 architecture may not work on all Pentium based boards.
213 People using multiprocessor machines who say Y here should also say
214 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
215 Management" code will be disabled if you say Y here.
217 See also <file:Documentation/i386/IO-APIC.txt>,
218 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
219 <http://www.tldp.org/docs.html#howto>.
221 If you don't know what to do here, say N.
224 prompt "Subarchitecture Type"
230 Choose this option if your computer is a standard PC or compatible.
236 Select this for an AMD Elan processor.
238 Do not use this option for K6/Athlon/Opteron processors!
240 If unsure, choose "PC-compatible" instead.
244 depends on X86_32 && (SMP || BROKEN)
246 Voyager is an MCA-based 32-way capable SMP architecture proprietary
247 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
251 If you do not specifically know you have a Voyager based machine,
252 say N here, otherwise the kernel you build will not be bootable.
255 bool "NUMAQ (IBM/Sequent)"
256 depends on SMP && X86_32
259 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
260 multiquad box. This changes the way that processors are bootstrapped,
261 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
262 You will need a new lynxer.elf file to flash your firmware with - send
263 email to <Martin.Bligh@us.ibm.com>.
266 bool "Summit/EXA (IBM x440)"
267 depends on X86_32 && SMP
269 This option is needed for IBM systems that use the Summit/EXA chipset.
270 In particular, it is needed for the x440.
272 If you don't have one of these computers, you should say N here.
273 If you want to build a NUMA kernel, you must select ACPI.
276 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
277 depends on X86_32 && SMP
279 This option is needed for the systems that have more than 8 CPUs
280 and if the system is not of any sub-arch type above.
282 If you don't have such a system, you should say N here.
285 bool "SGI 320/540 (Visual Workstation)"
288 The SGI Visual Workstation series is an IA32-based workstation
289 based on SGI systems chips with some legacy PC hardware attached.
291 Say Y here to create a kernel to run on the SGI 320 or 540.
293 A kernel compiled for the Visual Workstation will not run on PCs
294 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
296 config X86_GENERICARCH
297 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
300 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
301 It is intended for a generic binary kernel.
302 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
305 bool "Support for Unisys ES7000 IA32 series"
306 depends on X86_32 && SMP
308 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
309 supposed to run on an IA32-based Unisys ES7000 system.
310 Only choose this option if you have such a system, otherwise you
314 bool "RDC R-321x SoC"
317 select X86_REBOOTFIXUPS
322 This option is needed for RDC R-321x system-on-chip, also known
324 If you don't have one of these chips, you should say N here.
327 bool "Support for ScaleMP vSMP"
331 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
332 supposed to run on these EM64T-based machines. Only choose this option
333 if you have one of these machines.
337 config SCHED_NO_NO_OMIT_FRAME_POINTER
339 prompt "Single-depth WCHAN output"
342 Calculate simpler /proc/<PID>/wchan values. If this option
343 is disabled then wchan values will recurse back to the
344 caller function. This provides more accurate wchan values,
345 at the expense of slightly more scheduling overhead.
347 If in doubt, say "Y".
349 menuconfig PARAVIRT_GUEST
350 bool "Paravirtualized guest support"
352 Say Y here to get to see options related to running Linux under
353 various hypervisors. This option alone does not add any kernel code.
355 If you say N, all options in this submenu will be skipped and disabled.
359 source "arch/x86/xen/Kconfig"
362 bool "VMI Guest support"
365 depends on !(X86_VISWS || X86_VOYAGER)
367 VMI provides a paravirtualized interface to the VMware ESX server
368 (it could be used by other hypervisors in theory too, but is not
369 at the moment), by linking the kernel to a GPL-ed ROM module
370 provided by the hypervisor.
372 source "arch/x86/lguest/Kconfig"
375 bool "Enable paravirtualization code"
376 depends on !(X86_VISWS || X86_VOYAGER)
378 This changes the kernel so it can modify itself when it is run
379 under a hypervisor, potentially improving performance significantly
380 over full virtualization. However, when run without a hypervisor
381 the kernel is theoretically slower and slightly larger.
387 depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
390 config HAVE_ARCH_PARSE_SRAT
394 config X86_SUMMIT_NUMA
396 depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
398 config X86_CYCLONE_TIMER
400 depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
402 config ES7000_CLUSTERED_APIC
404 depends on SMP && X86_ES7000 && MPENTIUMIII
406 source "arch/x86/Kconfig.cpu"
410 prompt "HPET Timer Support" if X86_32
412 Use the IA-PC HPET (High Precision Event Timer) to manage
413 time in preference to the PIT and RTC, if a HPET is
415 HPET is the next generation timer replacing legacy 8254s.
416 The HPET provides a stable time base on SMP
417 systems, unlike the TSC, but it is more expensive to access,
418 as it is off-chip. You can find the HPET spec at
419 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
421 You can safely choose Y here. However, HPET will only be
422 activated if the platform and the BIOS support this feature.
423 Otherwise the 8254 will be used for timing services.
425 Choose N to continue using the legacy 8254 timer.
427 config HPET_EMULATE_RTC
429 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
431 # Mark as embedded because too many people got it wrong.
432 # The code disables itself when not needed.
434 bool "GART IOMMU support" if EMBEDDED
438 depends on X86_64 && PCI
440 Support for full DMA access of devices with 32bit memory access only
441 on systems with more than 3GB. This is usually needed for USB,
442 sound, many IDE/SATA chipsets and some other devices.
443 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
444 based hardware IOMMU and a software bounce buffer based IOMMU used
445 on Intel systems and as fallback.
446 The code is only active when needed (enough memory and limited
447 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
451 bool "IBM Calgary IOMMU support"
453 depends on X86_64 && PCI && EXPERIMENTAL
455 Support for hardware IOMMUs in IBM's xSeries x366 and x460
456 systems. Needed to run systems with more than 3GB of memory
457 properly with 32-bit PCI devices that do not support DAC
458 (Double Address Cycle). Calgary also supports bus level
459 isolation, where all DMAs pass through the IOMMU. This
460 prevents them from going anywhere except their intended
461 destination. This catches hard-to-find kernel bugs and
462 mis-behaving drivers and devices that do not use the DMA-API
463 properly to set up their DMA buffers. The IOMMU can be
464 turned off at boot time with the iommu=off parameter.
465 Normally the kernel will make the right choice by itself.
468 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
470 prompt "Should Calgary be enabled by default?"
471 depends on CALGARY_IOMMU
473 Should Calgary be enabled by default? if you choose 'y', Calgary
474 will be used (if it exists). If you choose 'n', Calgary will not be
475 used even if it exists. If you choose 'n' and would like to use
476 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
480 def_bool (CALGARY_IOMMU || GART_IOMMU)
482 # need this always selected by IOMMU for the VIA workaround
486 Support for software bounce buffers used on x86-64 systems
487 which don't have a hardware IOMMU (e.g. the current generation
488 of Intel's x86-64 CPUs). Using this PCI devices which can only
489 access 32-bits of memory can be used on systems with more than
490 3 GB of memory. If unsure, say Y.
494 int "Maximum number of CPUs (2-255)"
497 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
500 This allows you to specify the maximum number of CPUs which this
501 kernel will support. The maximum supported value is 255 and the
502 minimum value which makes sense is 2.
504 This is purely to save memory - each supported CPU adds
505 approximately eight kilobytes to the kernel image.
508 bool "SMT (Hyperthreading) scheduler support"
511 SMT scheduler support improves the CPU scheduler's decision making
512 when dealing with Intel Pentium 4 chips with HyperThreading at a
513 cost of slightly increased overhead in some places. If unsure say
518 prompt "Multi-core scheduler support"
521 Multi-core scheduler support improves the CPU scheduler's decision
522 making when dealing with multi-core CPU chips at a cost of slightly
523 increased overhead in some places. If unsure say N here.
525 source "kernel/Kconfig.preempt"
528 bool "Local APIC support on uniprocessors"
529 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
531 A local APIC (Advanced Programmable Interrupt Controller) is an
532 integrated interrupt controller in the CPU. If you have a single-CPU
533 system which has a processor with a local APIC, you can say Y here to
534 enable and use it. If you say Y here even though your machine doesn't
535 have a local APIC, then the kernel will still run with no slowdown at
536 all. The local APIC supports CPU-generated self-interrupts (timer,
537 performance counters), and the NMI watchdog which detects hard
541 bool "IO-APIC support on uniprocessors"
542 depends on X86_UP_APIC
544 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
545 SMP-capable replacement for PC-style interrupt controllers. Most
546 SMP systems and many recent uniprocessor systems have one.
548 If you have a single-CPU system with an IO-APIC, you can say Y here
549 to use it. If you say Y here even though your machine doesn't have
550 an IO-APIC, then the kernel will still run with no slowdown at all.
552 config X86_LOCAL_APIC
554 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
558 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
560 config X86_VISWS_APIC
562 depends on X86_32 && X86_VISWS
565 bool "Machine Check Exception"
566 depends on !X86_VOYAGER
568 Machine Check Exception support allows the processor to notify the
569 kernel if it detects a problem (e.g. overheating, component failure).
570 The action the kernel takes depends on the severity of the problem,
571 ranging from a warning message on the console, to halting the machine.
572 Your processor must be a Pentium or newer to support this - check the
573 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
574 have a design flaw which leads to false MCE events - hence MCE is
575 disabled on all P5 processors, unless explicitly enabled with "mce"
576 as a boot argument. Similarly, if MCE is built in and creates a
577 problem on some new non-standard machine, you can boot with "nomce"
578 to disable it. MCE support simply ignores non-MCE processors like
579 the 386 and 486, so nearly everyone can say Y here.
583 prompt "Intel MCE features"
584 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
586 Additional support for intel specific MCE features such as
591 prompt "AMD MCE features"
592 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
594 Additional support for AMD specific MCE features such as
595 the DRAM Error Threshold.
597 config X86_MCE_NONFATAL
598 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
599 depends on X86_32 && X86_MCE
601 Enabling this feature starts a timer that triggers every 5 seconds which
602 will look at the machine check registers to see if anything happened.
603 Non-fatal problems automatically get corrected (but still logged).
604 Disable this if you don't want to see these messages.
605 Seeing the messages this option prints out may be indicative of dying
606 or out-of-spec (ie, overclocked) hardware.
607 This option only does something on certain CPUs.
608 (AMD Athlon/Duron and Intel Pentium 4)
610 config X86_MCE_P4THERMAL
611 bool "check for P4 thermal throttling interrupt."
612 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
614 Enabling this feature will cause a message to be printed when the P4
615 enters thermal throttling.
618 bool "Enable VM86 support" if EMBEDDED
622 This option is required by programs like DOSEMU to run 16-bit legacy
623 code on X86 processors. It also may be needed by software like
624 XFree86 to initialize some video cards via BIOS. Disabling this
625 option saves about 6k.
628 tristate "Toshiba Laptop support"
631 This adds a driver to safely access the System Management Mode of
632 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
633 not work on models with a Phoenix BIOS. The System Management Mode
634 is used to set the BIOS and power saving options on Toshiba portables.
636 For information on utilities to make use of this driver see the
637 Toshiba Linux utilities web site at:
638 <http://www.buzzard.org.uk/toshiba/>.
640 Say Y if you intend to run this kernel on a Toshiba portable.
644 tristate "Dell laptop support"
646 This adds a driver to safely access the System Management Mode
647 of the CPU on the Dell Inspiron 8000. The System Management Mode
648 is used to read cpu temperature and cooling fan status and to
649 control the fans on the I8K portables.
651 This driver has been tested only on the Inspiron 8000 but it may
652 also work with other Dell laptops. You can force loading on other
653 models by passing the parameter `force=1' to the module. Use at
656 For information on utilities to make use of this driver see the
657 I8K Linux utilities web site at:
658 <http://people.debian.org/~dz/i8k/>
660 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
663 config X86_REBOOTFIXUPS
665 prompt "Enable X86 board specific fixups for reboot"
666 depends on X86_32 && X86
668 This enables chipset and/or board specific fixups to be done
669 in order to get reboot to work correctly. This is only needed on
670 some combinations of hardware and BIOS. The symptom, for which
671 this config is intended, is when reboot ends with a stalled/hung
674 Currently, the only fixup is for the Geode machines using
675 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
677 Say Y if you want to enable the fixup. Currently, it's safe to
678 enable this option even if you don't need it.
682 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
685 If you say Y here, you will be able to update the microcode on
686 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
687 Pentium III, Pentium 4, Xeon etc. You will obviously need the
688 actual microcode binary data itself which is not shipped with the
691 For latest news and information on obtaining all the required
692 ingredients for this driver, check:
693 <http://www.urbanmyth.org/microcode/>.
695 To compile this driver as a module, choose M here: the
696 module will be called microcode.
698 config MICROCODE_OLD_INTERFACE
703 tristate "/dev/cpu/*/msr - Model-specific register support"
705 This device gives privileged processes access to the x86
706 Model-Specific Registers (MSRs). It is a character device with
707 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
708 MSR accesses are directed to a specific CPU on multi-processor
712 tristate "/dev/cpu/*/cpuid - CPU information support"
714 This device gives processes access to the x86 CPUID instruction to
715 be executed on a specific processor. It is a character device
716 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
720 prompt "High Memory Support"
721 default HIGHMEM4G if !X86_NUMAQ
722 default HIGHMEM64G if X86_NUMAQ
727 depends on !X86_NUMAQ
729 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
730 However, the address space of 32-bit x86 processors is only 4
731 Gigabytes large. That means that, if you have a large amount of
732 physical memory, not all of it can be "permanently mapped" by the
733 kernel. The physical memory that's not permanently mapped is called
736 If you are compiling a kernel which will never run on a machine with
737 more than 1 Gigabyte total physical RAM, answer "off" here (default
738 choice and suitable for most users). This will result in a "3GB/1GB"
739 split: 3GB are mapped so that each process sees a 3GB virtual memory
740 space and the remaining part of the 4GB virtual memory space is used
741 by the kernel to permanently map as much physical memory as
744 If the machine has between 1 and 4 Gigabytes physical RAM, then
747 If more than 4 Gigabytes is used then answer "64GB" here. This
748 selection turns Intel PAE (Physical Address Extension) mode on.
749 PAE implements 3-level paging on IA32 processors. PAE is fully
750 supported by Linux, PAE mode is implemented on all recent Intel
751 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
752 then the kernel will not boot on CPUs that don't support PAE!
754 The actual amount of total physical memory will either be
755 auto detected or can be forced by using a kernel command line option
756 such as "mem=256M". (Try "man bootparam" or see the documentation of
757 your boot loader (lilo or loadlin) about how to pass options to the
758 kernel at boot time.)
760 If unsure, say "off".
764 depends on !X86_NUMAQ
766 Select this if you have a 32-bit processor and between 1 and 4
767 gigabytes of physical RAM.
771 depends on !M386 && !M486
774 Select this if you have a 32-bit processor and more than 4
775 gigabytes of physical RAM.
780 depends on EXPERIMENTAL
781 prompt "Memory split" if EMBEDDED
785 Select the desired split between kernel and user memory.
787 If the address range available to the kernel is less than the
788 physical memory installed, the remaining memory will be available
789 as "high memory". Accessing high memory is a little more costly
790 than low memory, as it needs to be mapped into the kernel first.
791 Note that increasing the kernel address space limits the range
792 available to user programs, making the address space there
793 tighter. Selecting anything other than the default 3G/1G split
794 will also likely make your kernel incompatible with binary-only
797 If you are not absolutely sure what you are doing, leave this
801 bool "3G/1G user/kernel split"
802 config VMSPLIT_3G_OPT
804 bool "3G/1G user/kernel split (for full 1G low memory)"
806 bool "2G/2G user/kernel split"
807 config VMSPLIT_2G_OPT
809 bool "2G/2G user/kernel split (for full 2G low memory)"
811 bool "1G/3G user/kernel split"
816 default 0xB0000000 if VMSPLIT_3G_OPT
817 default 0x80000000 if VMSPLIT_2G
818 default 0x78000000 if VMSPLIT_2G_OPT
819 default 0x40000000 if VMSPLIT_1G
825 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
829 prompt "PAE (Physical Address Extension) Support"
830 depends on X86_32 && !HIGHMEM4G
831 select RESOURCES_64BIT
833 PAE is required for NX support, and furthermore enables
834 larger swapspace support for non-overcommit purposes. It
835 has the cost of more pagetable lookup overhead, and also
836 consumes more pagetable space per process.
838 # Common NUMA Features
840 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
842 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL)
844 default y if (X86_NUMAQ || X86_SUMMIT)
846 Enable NUMA (Non Uniform Memory Access) support.
847 The kernel will try to allocate memory used by a CPU on the
848 local memory controller of the CPU and add some more
849 NUMA awareness to the kernel.
851 For i386 this is currently highly experimental and should be only
852 used for kernel development. It might also cause boot failures.
853 For x86_64 this is recommended on all multiprocessor Opteron systems.
854 If the system is EM64T, you should say N unless your system is
857 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
858 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
862 prompt "Old style AMD Opteron NUMA detection"
863 depends on X86_64 && NUMA && PCI
865 Enable K8 NUMA node topology detection. You should say Y here if
866 you have a multi processor AMD K8 system. This uses an old
867 method to read the NUMA configuration directly from the builtin
868 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
869 instead, which also takes priority if both are compiled in.
871 config X86_64_ACPI_NUMA
873 prompt "ACPI NUMA detection"
874 depends on X86_64 && NUMA && ACPI && PCI
877 Enable ACPI SRAT based node topology detection.
880 bool "NUMA emulation"
881 depends on X86_64 && NUMA
883 Enable NUMA emulation. A flat machine will be split
884 into virtual nodes when booted with "numa=fake=N", where N is the
885 number of nodes. This is only useful for debugging.
888 int "Max num nodes shift(1-15)"
890 default "6" if X86_64
891 default "4" if X86_NUMAQ
893 depends on NEED_MULTIPLE_NODES
895 config HAVE_ARCH_BOOTMEM_NODE
897 depends on X86_32 && NUMA
899 config ARCH_HAVE_MEMORY_PRESENT
901 depends on X86_32 && DISCONTIGMEM
903 config NEED_NODE_MEMMAP_SIZE
905 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
907 config HAVE_ARCH_ALLOC_REMAP
909 depends on X86_32 && NUMA
911 config ARCH_FLATMEM_ENABLE
913 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
915 config ARCH_DISCONTIGMEM_ENABLE
917 depends on NUMA && X86_32
919 config ARCH_DISCONTIGMEM_DEFAULT
921 depends on NUMA && X86_32
923 config ARCH_SPARSEMEM_DEFAULT
927 config ARCH_SPARSEMEM_ENABLE
929 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
930 select SPARSEMEM_STATIC if X86_32
931 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
933 config ARCH_SELECT_MEMORY_MODEL
935 depends on ARCH_SPARSEMEM_ENABLE
937 config ARCH_MEMORY_PROBE
939 depends on MEMORY_HOTPLUG
944 bool "Allocate 3rd-level pagetables from highmem"
945 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
947 The VM uses one page table entry for each page of physical memory.
948 For systems with a lot of RAM, this can be wasteful of precious
949 low memory. Setting this option will put user-space page table
950 entries in high memory.
952 config MATH_EMULATION
954 prompt "Math emulation" if X86_32
956 Linux can emulate a math coprocessor (used for floating point
957 operations) if you don't have one. 486DX and Pentium processors have
958 a math coprocessor built in, 486SX and 386 do not, unless you added
959 a 487DX or 387, respectively. (The messages during boot time can
960 give you some hints here ["man dmesg"].) Everyone needs either a
961 coprocessor or this emulation.
963 If you don't have a math coprocessor, you need to say Y here; if you
964 say Y here even though you have a coprocessor, the coprocessor will
965 be used nevertheless. (This behavior can be changed with the kernel
966 command line option "no387", which comes handy if your coprocessor
967 is broken. Try "man bootparam" or see the documentation of your boot
968 loader (lilo or loadlin) about how to pass options to the kernel at
969 boot time.) This means that it is a good idea to say Y here if you
970 intend to use this kernel on different machines.
972 More information about the internals of the Linux math coprocessor
973 emulation can be found in <file:arch/x86/math-emu/README>.
975 If you are not sure, say Y; apart from resulting in a 66 KB bigger
976 kernel, it won't hurt.
979 bool "MTRR (Memory Type Range Register) support"
981 On Intel P6 family processors (Pentium Pro, Pentium II and later)
982 the Memory Type Range Registers (MTRRs) may be used to control
983 processor access to memory ranges. This is most useful if you have
984 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
985 allows bus write transfers to be combined into a larger transfer
986 before bursting over the PCI/AGP bus. This can increase performance
987 of image write operations 2.5 times or more. Saying Y here creates a
988 /proc/mtrr file which may be used to manipulate your processor's
989 MTRRs. Typically the X server should use this.
991 This code has a reasonably generic interface so that similar
992 control registers on other processors can be easily supported
995 The Cyrix 6x86, 6x86MX and M II processors have Address Range
996 Registers (ARRs) which provide a similar functionality to MTRRs. For
997 these, the ARRs are used to emulate the MTRRs.
998 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
999 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1000 write-combining. All of these processors are supported by this code
1001 and it makes sense to say Y here if you have one of them.
1003 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1004 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1005 can lead to all sorts of problems, so it's good to say Y here.
1007 You can safely say Y even if your machine doesn't have MTRRs, you'll
1008 just add about 9 KB to your kernel.
1010 See <file:Documentation/mtrr.txt> for more information.
1014 prompt "x86 PAT support"
1015 depends on MTRR && NONPROMISC_DEVMEM
1017 Use PAT attributes to setup page level cache control.
1019 PATs are the modern equivalents of MTRRs and are much more
1020 flexible than MTRRs.
1022 Say N here if you see bootup problems (boot crash, boot hang,
1023 spontaneous reboots) or a non-working video driver.
1029 prompt "EFI runtime service support"
1032 This enables the kernel to use EFI runtime services that are
1033 available (such as the EFI variable services).
1035 This option is only useful on systems that have EFI firmware.
1036 In addition, you should use the latest ELILO loader available
1037 at <http://elilo.sourceforge.net> in order to take advantage
1038 of EFI runtime services. However, even with this option, the
1039 resultant kernel should continue to boot on existing non-EFI
1044 prompt "Enable kernel irq balancing"
1045 depends on X86_32 && SMP && X86_IO_APIC
1047 The default yes will allow the kernel to do irq load balancing.
1048 Saying no will keep the kernel from doing irq load balancing.
1052 prompt "Enable seccomp to safely compute untrusted bytecode"
1055 This kernel feature is useful for number crunching applications
1056 that may need to compute untrusted bytecode during their
1057 execution. By using pipes or other transports made available to
1058 the process as file descriptors supporting the read/write
1059 syscalls, it's possible to isolate those applications in
1060 their own address space using seccomp. Once seccomp is
1061 enabled via /proc/<pid>/seccomp, it cannot be disabled
1062 and the task is only allowed to execute a few safe syscalls
1063 defined by each seccomp mode.
1065 If unsure, say Y. Only embedded should say N here.
1067 config CC_STACKPROTECTOR
1068 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1069 depends on X86_64 && EXPERIMENTAL && BROKEN
1071 This option turns on the -fstack-protector GCC feature. This
1072 feature puts, at the beginning of critical functions, a canary
1073 value on the stack just before the return address, and validates
1074 the value just before actually returning. Stack based buffer
1075 overflows (that need to overwrite this return address) now also
1076 overwrite the canary, which gets detected and the attack is then
1077 neutralized via a kernel panic.
1079 This feature requires gcc version 4.2 or above, or a distribution
1080 gcc with the feature backported. Older versions are automatically
1081 detected and for those versions, this configuration option is ignored.
1083 config CC_STACKPROTECTOR_ALL
1084 bool "Use stack-protector for all functions"
1085 depends on CC_STACKPROTECTOR
1087 Normally, GCC only inserts the canary value protection for
1088 functions that use large-ish on-stack buffers. By enabling
1089 this option, GCC will be asked to do this for ALL functions.
1091 source kernel/Kconfig.hz
1094 bool "kexec system call"
1096 kexec is a system call that implements the ability to shutdown your
1097 current kernel, and to start another kernel. It is like a reboot
1098 but it is independent of the system firmware. And like a reboot
1099 you can start any kernel with it, not just Linux.
1101 The name comes from the similarity to the exec system call.
1103 It is an ongoing process to be certain the hardware in a machine
1104 is properly shutdown, so do not be surprised if this code does not
1105 initially work for you. It may help to enable device hotplugging
1106 support. As of this writing the exact hardware interface is
1107 strongly in flux, so no good recommendation can be made.
1110 bool "kernel crash dumps (EXPERIMENTAL)"
1111 depends on EXPERIMENTAL
1112 depends on X86_64 || (X86_32 && HIGHMEM)
1114 Generate crash dump after being started by kexec.
1115 This should be normally only set in special crash dump kernels
1116 which are loaded in the main kernel with kexec-tools into
1117 a specially reserved region and then later executed after
1118 a crash by kdump/kexec. The crash dump kernel must be compiled
1119 to a memory address not used by the main kernel or BIOS using
1120 PHYSICAL_START, or it must be built as a relocatable image
1121 (CONFIG_RELOCATABLE=y).
1122 For more details see Documentation/kdump/kdump.txt
1124 config PHYSICAL_START
1125 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1126 default "0x1000000" if X86_NUMAQ
1127 default "0x200000" if X86_64
1130 This gives the physical address where the kernel is loaded.
1132 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1133 bzImage will decompress itself to above physical address and
1134 run from there. Otherwise, bzImage will run from the address where
1135 it has been loaded by the boot loader and will ignore above physical
1138 In normal kdump cases one does not have to set/change this option
1139 as now bzImage can be compiled as a completely relocatable image
1140 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1141 address. This option is mainly useful for the folks who don't want
1142 to use a bzImage for capturing the crash dump and want to use a
1143 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1144 to be specifically compiled to run from a specific memory area
1145 (normally a reserved region) and this option comes handy.
1147 So if you are using bzImage for capturing the crash dump, leave
1148 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1149 Otherwise if you plan to use vmlinux for capturing the crash dump
1150 change this value to start of the reserved region (Typically 16MB
1151 0x1000000). In other words, it can be set based on the "X" value as
1152 specified in the "crashkernel=YM@XM" command line boot parameter
1153 passed to the panic-ed kernel. Typically this parameter is set as
1154 crashkernel=64M@16M. Please take a look at
1155 Documentation/kdump/kdump.txt for more details about crash dumps.
1157 Usage of bzImage for capturing the crash dump is recommended as
1158 one does not have to build two kernels. Same kernel can be used
1159 as production kernel and capture kernel. Above option should have
1160 gone away after relocatable bzImage support is introduced. But it
1161 is present because there are users out there who continue to use
1162 vmlinux for dump capture. This option should go away down the
1165 Don't change this unless you know what you are doing.
1168 bool "Build a relocatable kernel (EXPERIMENTAL)"
1169 depends on EXPERIMENTAL
1171 This builds a kernel image that retains relocation information
1172 so it can be loaded someplace besides the default 1MB.
1173 The relocations tend to make the kernel binary about 10% larger,
1174 but are discarded at runtime.
1176 One use is for the kexec on panic case where the recovery kernel
1177 must live at a different physical address than the primary
1180 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1181 it has been loaded at and the compile time physical address
1182 (CONFIG_PHYSICAL_START) is ignored.
1184 config PHYSICAL_ALIGN
1186 prompt "Alignment value to which kernel should be aligned" if X86_32
1187 default "0x100000" if X86_32
1188 default "0x200000" if X86_64
1189 range 0x2000 0x400000
1191 This value puts the alignment restrictions on physical address
1192 where kernel is loaded and run from. Kernel is compiled for an
1193 address which meets above alignment restriction.
1195 If bootloader loads the kernel at a non-aligned address and
1196 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1197 address aligned to above value and run from there.
1199 If bootloader loads the kernel at a non-aligned address and
1200 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1201 load address and decompress itself to the address it has been
1202 compiled for and run from there. The address for which kernel is
1203 compiled already meets above alignment restrictions. Hence the
1204 end result is that kernel runs from a physical address meeting
1205 above alignment restrictions.
1207 Don't change this unless you know what you are doing.
1210 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1211 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1213 Say Y here to experiment with turning CPUs off and on, and to
1214 enable suspend on SMP systems. CPUs can be controlled through
1215 /sys/devices/system/cpu.
1216 Say N if you want to disable CPU hotplug and don't need to
1221 prompt "Compat VDSO support"
1222 depends on X86_32 || IA32_EMULATION
1224 Map the 32-bit VDSO to the predictable old-style address too.
1226 Say N here if you are running a sufficiently recent glibc
1227 version (2.3.3 or later), to remove the high-mapped
1228 VDSO mapping and to exclusively use the randomized VDSO.
1234 config ARCH_ENABLE_MEMORY_HOTPLUG
1236 depends on X86_64 || (X86_32 && HIGHMEM)
1238 config HAVE_ARCH_EARLY_PFN_TO_NID
1242 menu "Power management options"
1243 depends on !X86_VOYAGER
1245 config ARCH_HIBERNATION_HEADER
1247 depends on X86_64 && HIBERNATION
1249 source "kernel/power/Kconfig"
1251 source "drivers/acpi/Kconfig"
1256 depends on APM || APM_MODULE
1259 tristate "APM (Advanced Power Management) BIOS support"
1260 depends on X86_32 && PM_SLEEP && !X86_VISWS
1262 APM is a BIOS specification for saving power using several different
1263 techniques. This is mostly useful for battery powered laptops with
1264 APM compliant BIOSes. If you say Y here, the system time will be
1265 reset after a RESUME operation, the /proc/apm device will provide
1266 battery status information, and user-space programs will receive
1267 notification of APM "events" (e.g. battery status change).
1269 If you select "Y" here, you can disable actual use of the APM
1270 BIOS by passing the "apm=off" option to the kernel at boot time.
1272 Note that the APM support is almost completely disabled for
1273 machines with more than one CPU.
1275 In order to use APM, you will need supporting software. For location
1276 and more information, read <file:Documentation/power/pm.txt> and the
1277 Battery Powered Linux mini-HOWTO, available from
1278 <http://www.tldp.org/docs.html#howto>.
1280 This driver does not spin down disk drives (see the hdparm(8)
1281 manpage ("man 8 hdparm") for that), and it doesn't turn off
1282 VESA-compliant "green" monitors.
1284 This driver does not support the TI 4000M TravelMate and the ACER
1285 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1286 desktop machines also don't have compliant BIOSes, and this driver
1287 may cause those machines to panic during the boot phase.
1289 Generally, if you don't have a battery in your machine, there isn't
1290 much point in using this driver and you should say N. If you get
1291 random kernel OOPSes or reboots that don't seem to be related to
1292 anything, try disabling/enabling this option (or disabling/enabling
1295 Some other things you should try when experiencing seemingly random,
1298 1) make sure that you have enough swap space and that it is
1300 2) pass the "no-hlt" option to the kernel
1301 3) switch on floating point emulation in the kernel and pass
1302 the "no387" option to the kernel
1303 4) pass the "floppy=nodma" option to the kernel
1304 5) pass the "mem=4M" option to the kernel (thereby disabling
1305 all but the first 4 MB of RAM)
1306 6) make sure that the CPU is not over clocked.
1307 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1308 8) disable the cache from your BIOS settings
1309 9) install a fan for the video card or exchange video RAM
1310 10) install a better fan for the CPU
1311 11) exchange RAM chips
1312 12) exchange the motherboard.
1314 To compile this driver as a module, choose M here: the
1315 module will be called apm.
1319 config APM_IGNORE_USER_SUSPEND
1320 bool "Ignore USER SUSPEND"
1322 This option will ignore USER SUSPEND requests. On machines with a
1323 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1324 series notebooks, it is necessary to say Y because of a BIOS bug.
1326 config APM_DO_ENABLE
1327 bool "Enable PM at boot time"
1329 Enable APM features at boot time. From page 36 of the APM BIOS
1330 specification: "When disabled, the APM BIOS does not automatically
1331 power manage devices, enter the Standby State, enter the Suspend
1332 State, or take power saving steps in response to CPU Idle calls."
1333 This driver will make CPU Idle calls when Linux is idle (unless this
1334 feature is turned off -- see "Do CPU IDLE calls", below). This
1335 should always save battery power, but more complicated APM features
1336 will be dependent on your BIOS implementation. You may need to turn
1337 this option off if your computer hangs at boot time when using APM
1338 support, or if it beeps continuously instead of suspending. Turn
1339 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1340 T400CDT. This is off by default since most machines do fine without
1344 bool "Make CPU Idle calls when idle"
1346 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1347 On some machines, this can activate improved power savings, such as
1348 a slowed CPU clock rate, when the machine is idle. These idle calls
1349 are made after the idle loop has run for some length of time (e.g.,
1350 333 mS). On some machines, this will cause a hang at boot time or
1351 whenever the CPU becomes idle. (On machines with more than one CPU,
1352 this option does nothing.)
1354 config APM_DISPLAY_BLANK
1355 bool "Enable console blanking using APM"
1357 Enable console blanking using the APM. Some laptops can use this to
1358 turn off the LCD backlight when the screen blanker of the Linux
1359 virtual console blanks the screen. Note that this is only used by
1360 the virtual console screen blanker, and won't turn off the backlight
1361 when using the X Window system. This also doesn't have anything to
1362 do with your VESA-compliant power-saving monitor. Further, this
1363 option doesn't work for all laptops -- it might not turn off your
1364 backlight at all, or it might print a lot of errors to the console,
1365 especially if you are using gpm.
1367 config APM_ALLOW_INTS
1368 bool "Allow interrupts during APM BIOS calls"
1370 Normally we disable external interrupts while we are making calls to
1371 the APM BIOS as a measure to lessen the effects of a badly behaving
1372 BIOS implementation. The BIOS should reenable interrupts if it
1373 needs to. Unfortunately, some BIOSes do not -- especially those in
1374 many of the newer IBM Thinkpads. If you experience hangs when you
1375 suspend, try setting this to Y. Otherwise, say N.
1377 config APM_REAL_MODE_POWER_OFF
1378 bool "Use real mode APM BIOS call to power off"
1380 Use real mode APM BIOS calls to switch off the computer. This is
1381 a work-around for a number of buggy BIOSes. Switch this option on if
1382 your computer crashes instead of powering off properly.
1386 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1388 source "drivers/cpuidle/Kconfig"
1393 menu "Bus options (PCI etc.)"
1396 bool "PCI support" if !X86_VISWS && !X86_VSMP
1397 depends on !X86_VOYAGER
1399 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1401 Find out whether you have a PCI motherboard. PCI is the name of a
1402 bus system, i.e. the way the CPU talks to the other stuff inside
1403 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1404 VESA. If you have PCI, say Y, otherwise N.
1407 prompt "PCI access mode"
1408 depends on X86_32 && PCI && !X86_VISWS
1411 On PCI systems, the BIOS can be used to detect the PCI devices and
1412 determine their configuration. However, some old PCI motherboards
1413 have BIOS bugs and may crash if this is done. Also, some embedded
1414 PCI-based systems don't have any BIOS at all. Linux can also try to
1415 detect the PCI hardware directly without using the BIOS.
1417 With this option, you can specify how Linux should detect the
1418 PCI devices. If you choose "BIOS", the BIOS will be used,
1419 if you choose "Direct", the BIOS won't be used, and if you
1420 choose "MMConfig", then PCI Express MMCONFIG will be used.
1421 If you choose "Any", the kernel will try MMCONFIG, then the
1422 direct access method and falls back to the BIOS if that doesn't
1423 work. If unsure, go with the default, which is "Any".
1428 config PCI_GOMMCONFIG
1441 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1443 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1446 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1450 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1457 bool "Support mmconfig PCI config space access"
1458 depends on X86_64 && PCI && ACPI
1461 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1462 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1464 DMA remapping (DMAR) devices support enables independent address
1465 translations for Direct Memory Access (DMA) from devices.
1466 These DMA remapping devices are reported via ACPI tables
1467 and include PCI device scope covered by these DMA
1472 prompt "Support for Graphics workaround"
1475 Current Graphics drivers tend to use physical address
1476 for DMA and avoid using DMA APIs. Setting this config
1477 option permits the IOMMU driver to set a unity map for
1478 all the OS-visible memory. Hence the driver can continue
1479 to use physical addresses for DMA.
1481 config DMAR_FLOPPY_WA
1485 Floppy disk drivers are know to bypass DMA API calls
1486 thereby failing to work when IOMMU is enabled. This
1487 workaround will setup a 1:1 mapping for the first
1488 16M to make floppy (an ISA device) work.
1490 source "drivers/pci/pcie/Kconfig"
1492 source "drivers/pci/Kconfig"
1494 # x86_64 have no ISA slots, but do have ISA-style DMA.
1502 depends on !(X86_VOYAGER || X86_VISWS)
1504 Find out whether you have ISA slots on your motherboard. ISA is the
1505 name of a bus system, i.e. the way the CPU talks to the other stuff
1506 inside your box. Other bus systems are PCI, EISA, MicroChannel
1507 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1508 newer boards don't support it. If you have ISA, say Y, otherwise N.
1514 The Extended Industry Standard Architecture (EISA) bus was
1515 developed as an open alternative to the IBM MicroChannel bus.
1517 The EISA bus provided some of the features of the IBM MicroChannel
1518 bus while maintaining backward compatibility with cards made for
1519 the older ISA bus. The EISA bus saw limited use between 1988 and
1520 1995 when it was made obsolete by the PCI bus.
1522 Say Y here if you are building a kernel for an EISA-based machine.
1526 source "drivers/eisa/Kconfig"
1529 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1530 default y if X86_VOYAGER
1532 MicroChannel Architecture is found in some IBM PS/2 machines and
1533 laptops. It is a bus system similar to PCI or ISA. See
1534 <file:Documentation/mca.txt> (and especially the web page given
1535 there) before attempting to build an MCA bus kernel.
1537 source "drivers/mca/Kconfig"
1540 tristate "NatSemi SCx200 support"
1541 depends on !X86_VOYAGER
1543 This provides basic support for National Semiconductor's
1544 (now AMD's) Geode processors. The driver probes for the
1545 PCI-IDs of several on-chip devices, so its a good dependency
1546 for other scx200_* drivers.
1548 If compiled as a module, the driver is named scx200.
1550 config SCx200HR_TIMER
1551 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1552 depends on SCx200 && GENERIC_TIME
1555 This driver provides a clocksource built upon the on-chip
1556 27MHz high-resolution timer. Its also a workaround for
1557 NSC Geode SC-1100's buggy TSC, which loses time when the
1558 processor goes idle (as is done by the scheduler). The
1559 other workaround is idle=poll boot option.
1561 config GEODE_MFGPT_TIMER
1563 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1564 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1566 This driver provides a clock event source based on the MFGPT
1567 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1568 MFGPTs have a better resolution and max interval than the
1569 generic PIT, and are suitable for use as high-res timers.
1575 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1577 source "drivers/pcmcia/Kconfig"
1579 source "drivers/pci/hotplug/Kconfig"
1584 menu "Executable file formats / Emulations"
1586 source "fs/Kconfig.binfmt"
1588 config IA32_EMULATION
1589 bool "IA32 Emulation"
1591 select COMPAT_BINFMT_ELF
1593 Include code to run 32-bit programs under a 64-bit kernel. You should
1594 likely turn this on, unless you're 100% sure that you don't have any
1595 32-bit programs left.
1598 tristate "IA32 a.out support"
1599 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1601 Support old a.out binaries in the 32bit emulation.
1605 depends on IA32_EMULATION
1607 config COMPAT_FOR_U64_ALIGNMENT
1611 config SYSVIPC_COMPAT
1613 depends on X86_64 && COMPAT && SYSVIPC
1618 source "net/Kconfig"
1620 source "drivers/Kconfig"
1622 source "drivers/firmware/Kconfig"
1626 source "arch/x86/Kconfig.debug"
1628 source "security/Kconfig"
1630 source "crypto/Kconfig"
1632 source "arch/x86/kvm/Kconfig"
1634 source "lib/Kconfig"