2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
5 # Note: ISA is disabled and will hopefully never be enabled.
6 # If you managed to buy an ISA x86-64 box you'll have to fix all the
7 # ISA drivers you need yourself.
10 mainmenu "Linux Kernel Configuration"
16 Port to the x86-64 architecture. x86-64 is a 64-bit extension to the
17 classical 32-bit x86 architecture. For details see
18 <http://www.x86-64.org/>.
31 config GENERIC_TIME_VSYSCALL
35 config GENERIC_CMOS_UPDATE
39 config CLOCKSOURCE_WATCHDOG
43 config GENERIC_CLOCKEVENTS
47 config GENERIC_CLOCKEVENTS_BROADCAST
55 config LOCKDEP_SUPPORT
59 config STACKTRACE_SUPPORT
63 config SEMAPHORE_SLEEPERS
81 config RWSEM_GENERIC_SPINLOCK
85 config RWSEM_XCHGADD_ALGORITHM
88 config GENERIC_HWEIGHT
92 config GENERIC_CALIBRATE_DELAY
104 config GENERIC_ISA_DMA
112 config ARCH_MAY_HAVE_PC_FDC
116 config ARCH_POPULATES_NODE_MAP
132 config ARCH_HAS_ILOG2_U32
136 config ARCH_HAS_ILOG2_U64
140 source "init/Kconfig"
143 menu "Processor type and features"
145 source "kernel/time/Kconfig"
148 prompt "Subarchitecture Type"
154 Choose this option if your computer is a standard PC or compatible.
157 bool "Support for ScaleMP vSMP"
160 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
161 supposed to run on these EM64T-based machines. Only choose this option
162 if you have one of these machines.
167 prompt "Processor family"
171 bool "AMD-Opteron/Athlon64"
173 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
176 bool "Intel P4 / older Netburst based Xeon"
178 Optimize for Intel Pentium 4, Pentium D and older Nocona/Dempsey
179 Xeon CPUs with Intel 64bit which is compatible with x86-64.
180 Note that the latest Xeons (Xeon 51xx and 53xx) are not based on the
181 Netburst core and shouldn't use this option. You can distinguish them
182 using the cpu family field
183 in /proc/cpuinfo. Family 15 is an older Xeon, Family 6 a newer one.
186 bool "Intel Core2 / newer Xeon"
188 Optimize for Intel Core2 and newer Xeons (51xx)
189 You can distinguish the newer Xeons from the older ones using
190 the cpu family field in /proc/cpuinfo. 15 is an older Xeon
191 (use CONFIG_MPSC then), 6 is a newer one.
194 bool "Generic-x86-64"
197 Run equally well on all x86-64 CPUs.
202 # Define implied options from the CPU selection here
204 config X86_L1_CACHE_BYTES
206 default "128" if GENERIC_CPU || MPSC
207 default "64" if MK8 || MCORE2
209 config X86_L1_CACHE_SHIFT
211 default "7" if GENERIC_CPU || MPSC
212 default "6" if MK8 || MCORE2
214 config X86_INTERNODE_CACHE_BYTES
216 default "4096" if X86_VSMP
217 default X86_L1_CACHE_BYTES if !X86_VSMP
228 tristate "/dev/cpu/microcode - Intel CPU microcode support"
231 If you say Y here the 'File systems' section, you will be
232 able to update the microcode on Intel processors. You will
233 obviously need the actual microcode binary data itself which is
234 not shipped with the Linux kernel.
236 For latest news and information on obtaining all the required
237 ingredients for this driver, check:
238 <http://www.urbanmyth.org/microcode/>.
240 To compile this driver as a module, choose M here: the
241 module will be called microcode.
242 If you use modprobe or kmod you may also want to add the line
243 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
245 config MICROCODE_OLD_INTERFACE
251 tristate "/dev/cpu/*/msr - Model-specific register support"
253 This device gives privileged processes access to the x86
254 Model-Specific Registers (MSRs). It is a character device with
255 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
256 MSR accesses are directed to a specific CPU on multi-processor
260 tristate "/dev/cpu/*/cpuid - CPU information support"
262 This device gives processes access to the x86 CPUID instruction to
263 be executed on a specific processor. It is a character device
264 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
269 depends on SMP && !MK8
272 config MATH_EMULATION
285 config X86_LOCAL_APIC
290 bool "MTRR (Memory Type Range Register) support"
292 On Intel P6 family processors (Pentium Pro, Pentium II and later)
293 the Memory Type Range Registers (MTRRs) may be used to control
294 processor access to memory ranges. This is most useful if you have
295 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
296 allows bus write transfers to be combined into a larger transfer
297 before bursting over the PCI/AGP bus. This can increase performance
298 of image write operations 2.5 times or more. Saying Y here creates a
299 /proc/mtrr file which may be used to manipulate your processor's
300 MTRRs. Typically the X server should use this.
302 This code has a reasonably generic interface so that similar
303 control registers on other processors can be easily supported
306 Saying Y here also fixes a problem with buggy SMP BIOSes which only
307 set the MTRRs for the boot CPU and not for the secondary CPUs. This
308 can lead to all sorts of problems, so it's good to say Y here.
310 Just say Y here, all x86-64 machines support MTRRs.
312 See <file:Documentation/mtrr.txt> for more information.
315 bool "Symmetric multi-processing support"
317 This enables support for systems with more than one CPU. If you have
318 a system with only one CPU, like most personal computers, say N. If
319 you have a system with more than one CPU, say Y.
321 If you say N here, the kernel will run on single and multiprocessor
322 machines, but will use only one CPU of a multiprocessor machine. If
323 you say Y here, the kernel will run on many, but not all,
324 singleprocessor machines. On a singleprocessor machine, the kernel
325 will run faster if you say N here.
327 If you don't know what to do here, say N.
330 bool "SMT (Hyperthreading) scheduler support"
334 SMT scheduler support improves the CPU scheduler's decision making
335 when dealing with Intel Pentium 4 chips with HyperThreading at a
336 cost of slightly increased overhead in some places. If unsure say
340 bool "Multi-core scheduler support"
344 Multi-core scheduler support improves the CPU scheduler's decision
345 making when dealing with multi-core CPU chips at a cost of slightly
346 increased overhead in some places. If unsure say N here.
348 source "kernel/Kconfig.preempt"
351 bool "Non Uniform Memory Access (NUMA) Support"
354 Enable NUMA (Non Uniform Memory Access) support. The kernel
355 will try to allocate memory used by a CPU on the local memory
356 controller of the CPU and add some more NUMA awareness to the kernel.
357 This code is recommended on all multiprocessor Opteron systems.
358 If the system is EM64T, you should say N unless your system is EM64T
362 bool "Old style AMD Opteron NUMA detection"
363 depends on NUMA && PCI
366 Enable K8 NUMA node topology detection. You should say Y here if
367 you have a multi processor AMD K8 system. This uses an old
368 method to read the NUMA configuration directly from the builtin
369 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
370 instead, which also takes priority if both are compiled in.
375 depends on NEED_MULTIPLE_NODES
377 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
379 config X86_64_ACPI_NUMA
380 bool "ACPI NUMA detection"
387 Enable ACPI SRAT based node topology detection.
390 bool "NUMA emulation"
393 Enable NUMA emulation. A flat machine will be split
394 into virtual nodes when booted with "numa=fake=N", where N is the
395 number of nodes. This is only useful for debugging.
397 config ARCH_DISCONTIGMEM_ENABLE
402 config ARCH_DISCONTIGMEM_DEFAULT
406 config ARCH_SPARSEMEM_ENABLE
408 depends on (NUMA || EXPERIMENTAL)
409 select SPARSEMEM_VMEMMAP_ENABLE
411 config ARCH_MEMORY_PROBE
413 depends on MEMORY_HOTPLUG
415 config ARCH_FLATMEM_ENABLE
421 config MEMORY_HOTPLUG_RESERVE
423 depends on (MEMORY_HOTPLUG && DISCONTIGMEM)
425 config HAVE_ARCH_EARLY_PFN_TO_NID
429 config OUT_OF_LINE_PFN_TO_PAGE
431 depends on DISCONTIGMEM
434 int "Maximum number of CPUs (2-255)"
439 This allows you to specify the maximum number of CPUs which this
440 kernel will support. Current maximum is 255 CPUs due to
441 APIC addressing limits. Less depending on the hardware.
443 This is purely to save memory - each supported CPU requires
444 memory in the static kernel configuration.
446 config PHYSICAL_ALIGN
451 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
452 depends on SMP && HOTPLUG && EXPERIMENTAL
454 Say Y here to experiment with turning CPUs off and on. CPUs
455 can be controlled through /sys/devices/system/cpu/cpu#.
456 This is also required for suspend/hibernation on SMP systems.
458 Say N if you want to disable CPU hotplug and don't need to
461 config ARCH_ENABLE_MEMORY_HOTPLUG
468 Use the IA-PC HPET (High Precision Event Timer) to manage
469 time in preference to the PIT and RTC, if a HPET is
470 present. The HPET provides a stable time base on SMP
471 systems, unlike the TSC, but it is more expensive to access,
472 as it is off-chip. You can find the HPET spec at
473 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
475 config HPET_EMULATE_RTC
477 depends on HPET_TIMER && RTC=y
480 # Mark as embedded because too many people got it wrong.
481 # The code disables itself when not needed.
483 bool "IOMMU support" if EMBEDDED
489 Support for full DMA access of devices with 32bit memory access only
490 on systems with more than 3GB. This is usually needed for USB,
491 sound, many IDE/SATA chipsets and some other devices.
492 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
493 based hardware IOMMU and a software bounce buffer based IOMMU used
494 on Intel systems and as fallback.
495 The code is only active when needed (enough memory and limited
496 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
500 bool "IBM Calgary IOMMU support"
502 depends on PCI && EXPERIMENTAL
504 Support for hardware IOMMUs in IBM's xSeries x366 and x460
505 systems. Needed to run systems with more than 3GB of memory
506 properly with 32-bit PCI devices that do not support DAC
507 (Double Address Cycle). Calgary also supports bus level
508 isolation, where all DMAs pass through the IOMMU. This
509 prevents them from going anywhere except their intended
510 destination. This catches hard-to-find kernel bugs and
511 mis-behaving drivers and devices that do not use the DMA-API
512 properly to set up their DMA buffers. The IOMMU can be
513 turned off at boot time with the iommu=off parameter.
514 Normally the kernel will make the right choice by itself.
517 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
518 bool "Should Calgary be enabled by default?"
520 depends on CALGARY_IOMMU
522 Should Calgary be enabled by default? if you choose 'y', Calgary
523 will be used (if it exists). If you choose 'n', Calgary will not be
524 used even if it exists. If you choose 'n' and would like to use
525 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
528 # need this always selected by IOMMU for the VIA workaround
532 Support for software bounce buffers used on x86-64 systems
533 which don't have a hardware IOMMU (e.g. the current generation
534 of Intel's x86-64 CPUs). Using this PCI devices which can only
535 access 32-bits of memory can be used on systems with more than
536 3 GB of memory. If unsure, say Y.
539 bool "Machine check support" if EMBEDDED
542 Include a machine check error handler to report hardware errors.
543 This version will require the mcelog utility to decode some
544 machine check error logs. See
545 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
548 bool "Intel MCE features"
549 depends on X86_MCE && X86_LOCAL_APIC
552 Additional support for intel specific MCE features such as
556 bool "AMD MCE features"
557 depends on X86_MCE && X86_LOCAL_APIC
560 Additional support for AMD specific MCE features such as
561 the DRAM Error Threshold.
564 bool "kexec system call"
566 kexec is a system call that implements the ability to shutdown your
567 current kernel, and to start another kernel. It is like a reboot
568 but it is independent of the system firmware. And like a reboot
569 you can start any kernel with it, not just Linux.
571 The name comes from the similarity to the exec system call.
573 It is an ongoing process to be certain the hardware in a machine
574 is properly shutdown, so do not be surprised if this code does not
575 initially work for you. It may help to enable device hotplugging
576 support. As of this writing the exact hardware interface is
577 strongly in flux, so no good recommendation can be made.
580 bool "kernel crash dumps (EXPERIMENTAL)"
581 depends on EXPERIMENTAL
583 Generate crash dump after being started by kexec.
584 This should be normally only set in special crash dump kernels
585 which are loaded in the main kernel with kexec-tools into
586 a specially reserved region and then later executed after
587 a crash by kdump/kexec. The crash dump kernel must be compiled
588 to a memory address not used by the main kernel or BIOS using
589 PHYSICAL_START, or it must be built as a relocatable image
590 (CONFIG_RELOCATABLE=y).
591 For more details see Documentation/kdump/kdump.txt
594 bool "Build a relocatable kernel (EXPERIMENTAL)"
595 depends on EXPERIMENTAL
597 Builds a relocatable kernel. This enables loading and running
598 a kernel binary from a different physical address than it has
601 One use is for the kexec on panic case where the recovery kernel
602 must live at a different physical address than the primary
605 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
606 it has been loaded at and the compile time physical address
607 (CONFIG_PHYSICAL_START) is ignored.
609 config PHYSICAL_START
610 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
613 This gives the physical address where the kernel is loaded. It
614 should be aligned to 2MB boundary.
616 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
617 bzImage will decompress itself to above physical address and
618 run from there. Otherwise, bzImage will run from the address where
619 it has been loaded by the boot loader and will ignore above physical
622 In normal kdump cases one does not have to set/change this option
623 as now bzImage can be compiled as a completely relocatable image
624 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
625 address. This option is mainly useful for the folks who don't want
626 to use a bzImage for capturing the crash dump and want to use a
629 So if you are using bzImage for capturing the crash dump, leave
630 the value here unchanged to 0x200000 and set CONFIG_RELOCATABLE=y.
631 Otherwise if you plan to use vmlinux for capturing the crash dump
632 change this value to start of the reserved region (Typically 16MB
633 0x1000000). In other words, it can be set based on the "X" value as
634 specified in the "crashkernel=YM@XM" command line boot parameter
635 passed to the panic-ed kernel. Typically this parameter is set as
636 crashkernel=64M@16M. Please take a look at
637 Documentation/kdump/kdump.txt for more details about crash dumps.
639 Usage of bzImage for capturing the crash dump is advantageous as
640 one does not have to build two kernels. Same kernel can be used
641 as production kernel and capture kernel.
643 Don't change this unless you know what you are doing.
646 bool "Enable seccomp to safely compute untrusted bytecode"
650 This kernel feature is useful for number crunching applications
651 that may need to compute untrusted bytecode during their
652 execution. By using pipes or other transports made available to
653 the process as file descriptors supporting the read/write
654 syscalls, it's possible to isolate those applications in
655 their own address space using seccomp. Once seccomp is
656 enabled via /proc/<pid>/seccomp, it cannot be disabled
657 and the task is only allowed to execute a few safe syscalls
658 defined by each seccomp mode.
660 If unsure, say Y. Only embedded should say N here.
662 config CC_STACKPROTECTOR
663 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
664 depends on EXPERIMENTAL
666 This option turns on the -fstack-protector GCC feature. This
667 feature puts, at the beginning of critical functions, a canary
668 value on the stack just before the return address, and validates
669 the value just before actually returning. Stack based buffer
670 overflows (that need to overwrite this return address) now also
671 overwrite the canary, which gets detected and the attack is then
672 neutralized via a kernel panic.
674 This feature requires gcc version 4.2 or above, or a distribution
675 gcc with the feature backported. Older versions are automatically
676 detected and for those versions, this configuration option is ignored.
678 config CC_STACKPROTECTOR_ALL
679 bool "Use stack-protector for all functions"
680 depends on CC_STACKPROTECTOR
682 Normally, GCC only inserts the canary value protection for
683 functions that use large-ish on-stack buffers. By enabling
684 this option, GCC will be asked to do this for ALL functions.
686 source kernel/Kconfig.hz
690 depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
695 # Use the generic interrupt handling code in kernel/irq/:
697 config GENERIC_HARDIRQS
701 config GENERIC_IRQ_PROBE
705 # we have no ISA slots, but we do have ISA-style DMA.
710 config GENERIC_PENDING_IRQ
712 depends on GENERIC_HARDIRQS && SMP
715 menu "Power management options"
717 source kernel/power/Kconfig
719 config ARCH_HIBERNATION_HEADER
721 depends on HIBERNATION
724 source "drivers/acpi/Kconfig"
726 source "arch/x86/kernel/cpu/cpufreq/Kconfig_64"
728 source "drivers/cpuidle/Kconfig"
732 menu "Bus options (PCI etc.)"
736 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
738 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
745 bool "Support mmconfig PCI config space access"
746 depends on PCI && ACPI
754 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
755 depends on PCI_MSI && ACPI && EXPERIMENTAL
758 DMA remapping (DMAR) devices support enables independent address
759 translations for Direct Memory Access (DMA) from devices.
760 These DMA remapping devices are reported via ACPI tables
761 and include PCI device scope covered by these DMA
765 bool "Support for Graphics workaround"
769 Current Graphics drivers tend to use physical address
770 for DMA and avoid using DMA APIs. Setting this config
771 option permits the IOMMU driver to set a unity map for
772 all the OS-visible memory. Hence the driver can continue
773 to use physical addresses for DMA.
775 config DMAR_FLOPPY_WA
780 Floppy disk drivers are know to bypass DMA API calls
781 thereby failing to work when IOMMU is enabled. This
782 workaround will setup a 1:1 mapping for the first
783 16M to make floppy (an ISA device) work.
785 source "drivers/pci/pcie/Kconfig"
787 source "drivers/pci/Kconfig"
789 source "drivers/pcmcia/Kconfig"
791 source "drivers/pci/hotplug/Kconfig"
796 menu "Executable file formats / Emulations"
798 source "fs/Kconfig.binfmt"
800 config IA32_EMULATION
801 bool "IA32 Emulation"
803 Include code to run 32-bit programs under a 64-bit kernel. You should
804 likely turn this on, unless you're 100% sure that you don't have any
805 32-bit programs left.
808 tristate "IA32 a.out support"
809 depends on IA32_EMULATION
811 Support old a.out binaries in the 32bit emulation.
815 depends on IA32_EMULATION
818 config COMPAT_FOR_U64_ALIGNMENT
821 config SYSVIPC_COMPAT
823 depends on COMPAT && SYSVIPC
830 source drivers/Kconfig
832 source "drivers/firmware/Kconfig"
836 source "arch/x86_64/Kconfig.debug"
838 source "security/Kconfig"
840 source "crypto/Kconfig"