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
43 config LOCKDEP_SUPPORT
47 config STACKTRACE_SUPPORT
51 config SEMAPHORE_SLEEPERS
77 config RWSEM_GENERIC_SPINLOCK
81 config RWSEM_XCHGADD_ALGORITHM
84 config GENERIC_HWEIGHT
88 config GENERIC_CALIBRATE_DELAY
100 config GENERIC_ISA_DMA
108 config ARCH_MAY_HAVE_PC_FDC
112 config ARCH_POPULATES_NODE_MAP
128 config ARCH_HAS_ILOG2_U32
132 config ARCH_HAS_ILOG2_U64
136 source "init/Kconfig"
139 menu "Processor type and features"
142 prompt "Subarchitecture Type"
148 Choose this option if your computer is a standard PC or compatible.
151 bool "Support for ScaleMP vSMP"
154 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
155 supposed to run on these EM64T-based machines. Only choose this option
156 if you have one of these machines.
161 prompt "Processor family"
165 bool "AMD-Opteron/Athlon64"
167 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
170 bool "Intel P4 / older Netburst based Xeon"
172 Optimize for Intel Pentium 4 and older Nocona/Dempsey Xeon CPUs
173 with Intel Extended Memory 64 Technology(EM64T). For details see
174 <http://www.intel.com/technology/64bitextensions/>.
175 Note that the latest Xeons (Xeon 51xx and 53xx) are not based on the
176 Netburst core and shouldn't use this option. You can distinguish them
177 using the cpu family field
178 in /proc/cpuinfo. Family 15 is an older Xeon, Family 6 a newer one
179 (this rule only applies to systems that support EM64T)
182 bool "Intel Core2 / newer Xeon"
184 Optimize for Intel Core2 and newer Xeons (51xx)
185 You can distinguish the newer Xeons from the older ones using
186 the cpu family field in /proc/cpuinfo. 15 is an older Xeon
187 (use CONFIG_MPSC then), 6 is a newer one. This rule only
188 applies to CPUs that support EM64T.
191 bool "Generic-x86-64"
194 Run equally well on all x86-64 CPUs.
199 # Define implied options from the CPU selection here
201 config X86_L1_CACHE_BYTES
203 default "128" if GENERIC_CPU || MPSC
204 default "64" if MK8 || MCORE2
206 config X86_L1_CACHE_SHIFT
208 default "7" if GENERIC_CPU || MPSC
209 default "6" if MK8 || MCORE2
211 config X86_INTERNODE_CACHE_BYTES
213 default "4096" if X86_VSMP
214 default X86_L1_CACHE_BYTES if !X86_VSMP
225 tristate "/dev/cpu/microcode - Intel CPU microcode support"
228 If you say Y here the 'File systems' section, you will be
229 able to update the microcode on Intel processors. You will
230 obviously need the actual microcode binary data itself which is
231 not shipped with the Linux kernel.
233 For latest news and information on obtaining all the required
234 ingredients for this driver, check:
235 <http://www.urbanmyth.org/microcode/>.
237 To compile this driver as a module, choose M here: the
238 module will be called microcode.
239 If you use modprobe or kmod you may also want to add the line
240 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
242 config MICROCODE_OLD_INTERFACE
248 tristate "/dev/cpu/*/msr - Model-specific register support"
250 This device gives privileged processes access to the x86
251 Model-Specific Registers (MSRs). It is a character device with
252 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
253 MSR accesses are directed to a specific CPU on multi-processor
257 tristate "/dev/cpu/*/cpuid - CPU information support"
259 This device gives processes access to the x86 CPUID instruction to
260 be executed on a specific processor. It is a character device
261 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
266 depends on SMP && !MK8
269 config MATH_EMULATION
282 config X86_LOCAL_APIC
287 bool "MTRR (Memory Type Range Register) support"
289 On Intel P6 family processors (Pentium Pro, Pentium II and later)
290 the Memory Type Range Registers (MTRRs) may be used to control
291 processor access to memory ranges. This is most useful if you have
292 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
293 allows bus write transfers to be combined into a larger transfer
294 before bursting over the PCI/AGP bus. This can increase performance
295 of image write operations 2.5 times or more. Saying Y here creates a
296 /proc/mtrr file which may be used to manipulate your processor's
297 MTRRs. Typically the X server should use this.
299 This code has a reasonably generic interface so that similar
300 control registers on other processors can be easily supported
303 Saying Y here also fixes a problem with buggy SMP BIOSes which only
304 set the MTRRs for the boot CPU and not for the secondary CPUs. This
305 can lead to all sorts of problems, so it's good to say Y here.
307 Just say Y here, all x86-64 machines support MTRRs.
309 See <file:Documentation/mtrr.txt> for more information.
312 bool "Symmetric multi-processing support"
314 This enables support for systems with more than one CPU. If you have
315 a system with only one CPU, like most personal computers, say N. If
316 you have a system with more than one CPU, say Y.
318 If you say N here, the kernel will run on single and multiprocessor
319 machines, but will use only one CPU of a multiprocessor machine. If
320 you say Y here, the kernel will run on many, but not all,
321 singleprocessor machines. On a singleprocessor machine, the kernel
322 will run faster if you say N here.
324 If you don't know what to do here, say N.
327 bool "SMT (Hyperthreading) scheduler support"
331 SMT scheduler support improves the CPU scheduler's decision making
332 when dealing with Intel Pentium 4 chips with HyperThreading at a
333 cost of slightly increased overhead in some places. If unsure say
337 bool "Multi-core scheduler support"
341 Multi-core scheduler support improves the CPU scheduler's decision
342 making when dealing with multi-core CPU chips at a cost of slightly
343 increased overhead in some places. If unsure say N here.
345 source "kernel/Kconfig.preempt"
348 bool "Non Uniform Memory Access (NUMA) Support"
351 Enable NUMA (Non Uniform Memory Access) support. The kernel
352 will try to allocate memory used by a CPU on the local memory
353 controller of the CPU and add some more NUMA awareness to the kernel.
354 This code is recommended on all multiprocessor Opteron systems.
355 If the system is EM64T, you should say N unless your system is EM64T
359 bool "Old style AMD Opteron NUMA detection"
360 depends on NUMA && PCI
363 Enable K8 NUMA node topology detection. You should say Y here if
364 you have a multi processor AMD K8 system. This uses an old
365 method to read the NUMA configuration directly from the builtin
366 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
367 instead, which also takes priority if both are compiled in.
372 depends on NEED_MULTIPLE_NODES
374 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
376 config X86_64_ACPI_NUMA
377 bool "ACPI NUMA detection"
384 Enable ACPI SRAT based node topology detection.
387 bool "NUMA emulation"
390 Enable NUMA emulation. A flat machine will be split
391 into virtual nodes when booted with "numa=fake=N", where N is the
392 number of nodes. This is only useful for debugging.
394 config ARCH_DISCONTIGMEM_ENABLE
399 config ARCH_DISCONTIGMEM_DEFAULT
403 config ARCH_SPARSEMEM_ENABLE
405 depends on (NUMA || EXPERIMENTAL)
407 config ARCH_MEMORY_PROBE
409 depends on MEMORY_HOTPLUG
411 config ARCH_FLATMEM_ENABLE
417 config MEMORY_HOTPLUG_RESERVE
419 depends on (MEMORY_HOTPLUG && DISCONTIGMEM)
421 config HAVE_ARCH_EARLY_PFN_TO_NID
425 config OUT_OF_LINE_PFN_TO_PAGE
427 depends on DISCONTIGMEM
430 int "Maximum number of CPUs (2-255)"
435 This allows you to specify the maximum number of CPUs which this
436 kernel will support. Current maximum is 255 CPUs due to
437 APIC addressing limits. Less depending on the hardware.
439 This is purely to save memory - each supported CPU requires
440 memory in the static kernel configuration.
442 config PHYSICAL_ALIGN
447 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
448 depends on SMP && HOTPLUG && EXPERIMENTAL
450 Say Y here to experiment with turning CPUs off and on. CPUs
451 can be controlled through /sys/devices/system/cpu/cpu#.
452 This is also required for suspend/hibernation on SMP systems.
454 Say N if you want to disable CPU hotplug and don't need to
457 config ARCH_ENABLE_MEMORY_HOTPLUG
464 Use the IA-PC HPET (High Precision Event Timer) to manage
465 time in preference to the PIT and RTC, if a HPET is
466 present. The HPET provides a stable time base on SMP
467 systems, unlike the TSC, but it is more expensive to access,
468 as it is off-chip. You can find the HPET spec at
469 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
471 config HPET_EMULATE_RTC
472 bool "Provide RTC interrupt"
473 depends on HPET_TIMER && RTC=y
475 # Mark as embedded because too many people got it wrong.
476 # The code disables itself when not needed.
478 bool "IOMMU support" if EMBEDDED
484 Support for full DMA access of devices with 32bit memory access only
485 on systems with more than 3GB. This is usually needed for USB,
486 sound, many IDE/SATA chipsets and some other devices.
487 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
488 based hardware IOMMU and a software bounce buffer based IOMMU used
489 on Intel systems and as fallback.
490 The code is only active when needed (enough memory and limited
491 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
495 bool "IBM Calgary IOMMU support"
497 depends on PCI && EXPERIMENTAL
499 Support for hardware IOMMUs in IBM's xSeries x366 and x460
500 systems. Needed to run systems with more than 3GB of memory
501 properly with 32-bit PCI devices that do not support DAC
502 (Double Address Cycle). Calgary also supports bus level
503 isolation, where all DMAs pass through the IOMMU. This
504 prevents them from going anywhere except their intended
505 destination. This catches hard-to-find kernel bugs and
506 mis-behaving drivers and devices that do not use the DMA-API
507 properly to set up their DMA buffers. The IOMMU can be
508 turned off at boot time with the iommu=off parameter.
509 Normally the kernel will make the right choice by itself.
512 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
513 bool "Should Calgary be enabled by default?"
515 depends on CALGARY_IOMMU
517 Should Calgary be enabled by default? if you choose 'y', Calgary
518 will be used (if it exists). If you choose 'n', Calgary will not be
519 used even if it exists. If you choose 'n' and would like to use
520 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
523 # need this always selected by IOMMU for the VIA workaround
527 Support for software bounce buffers used on x86-64 systems
528 which don't have a hardware IOMMU (e.g. the current generation
529 of Intel's x86-64 CPUs). Using this PCI devices which can only
530 access 32-bits of memory can be used on systems with more than
531 3 GB of memory. If unsure, say Y.
534 bool "Machine check support" if EMBEDDED
537 Include a machine check error handler to report hardware errors.
538 This version will require the mcelog utility to decode some
539 machine check error logs. See
540 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
543 bool "Intel MCE features"
544 depends on X86_MCE && X86_LOCAL_APIC
547 Additional support for intel specific MCE features such as
551 bool "AMD MCE features"
552 depends on X86_MCE && X86_LOCAL_APIC
555 Additional support for AMD specific MCE features such as
556 the DRAM Error Threshold.
559 bool "kexec system call"
561 kexec is a system call that implements the ability to shutdown your
562 current kernel, and to start another kernel. It is like a reboot
563 but it is independent of the system firmware. And like a reboot
564 you can start any kernel with it, not just Linux.
566 The name comes from the similarity to the exec system call.
568 It is an ongoing process to be certain the hardware in a machine
569 is properly shutdown, so do not be surprised if this code does not
570 initially work for you. It may help to enable device hotplugging
571 support. As of this writing the exact hardware interface is
572 strongly in flux, so no good recommendation can be made.
575 bool "kernel crash dumps (EXPERIMENTAL)"
576 depends on EXPERIMENTAL
578 Generate crash dump after being started by kexec.
579 This should be normally only set in special crash dump kernels
580 which are loaded in the main kernel with kexec-tools into
581 a specially reserved region and then later executed after
582 a crash by kdump/kexec. The crash dump kernel must be compiled
583 to a memory address not used by the main kernel or BIOS using
585 For more details see Documentation/kdump/kdump.txt
588 bool "Build a relocatable kernel(EXPERIMENTAL)"
589 depends on EXPERIMENTAL
591 Builds a relocatable kernel. This enables loading and running
592 a kernel binary from a different physical address than it has
595 One use is for the kexec on panic case where the recovery kernel
596 must live at a different physical address than the primary
599 Note: If CONFIG_RELOCATABLE=y, then kernel run from the address
600 it has been loaded at and compile time physical address
601 (CONFIG_PHYSICAL_START) is ignored.
603 config PHYSICAL_START
604 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
607 This gives the physical address where the kernel is loaded. It
608 should be aligned to 2MB boundary.
610 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
611 bzImage will decompress itself to above physical address and
612 run from there. Otherwise, bzImage will run from the address where
613 it has been loaded by the boot loader and will ignore above physical
616 In normal kdump cases one does not have to set/change this option
617 as now bzImage can be compiled as a completely relocatable image
618 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
619 address. This option is mainly useful for the folks who don't want
620 to use a bzImage for capturing the crash dump and want to use a
623 So if you are using bzImage for capturing the crash dump, leave
624 the value here unchanged to 0x200000 and set CONFIG_RELOCATABLE=y.
625 Otherwise if you plan to use vmlinux for capturing the crash dump
626 change this value to start of the reserved region (Typically 16MB
627 0x1000000). In other words, it can be set based on the "X" value as
628 specified in the "crashkernel=YM@XM" command line boot parameter
629 passed to the panic-ed kernel. Typically this parameter is set as
630 crashkernel=64M@16M. Please take a look at
631 Documentation/kdump/kdump.txt for more details about crash dumps.
633 Usage of bzImage for capturing the crash dump is advantageous as
634 one does not have to build two kernels. Same kernel can be used
635 as production kernel and capture kernel.
637 Don't change this unless you know what you are doing.
640 bool "Enable seccomp to safely compute untrusted bytecode"
644 This kernel feature is useful for number crunching applications
645 that may need to compute untrusted bytecode during their
646 execution. By using pipes or other transports made available to
647 the process as file descriptors supporting the read/write
648 syscalls, it's possible to isolate those applications in
649 their own address space using seccomp. Once seccomp is
650 enabled via /proc/<pid>/seccomp, it cannot be disabled
651 and the task is only allowed to execute a few safe syscalls
652 defined by each seccomp mode.
654 If unsure, say Y. Only embedded should say N here.
656 config CC_STACKPROTECTOR
657 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
658 depends on EXPERIMENTAL
660 This option turns on the -fstack-protector GCC feature. This
661 feature puts, at the beginning of critical functions, a canary
662 value on the stack just before the return address, and validates
663 the value just before actually returning. Stack based buffer
664 overflows (that need to overwrite this return address) now also
665 overwrite the canary, which gets detected and the attack is then
666 neutralized via a kernel panic.
668 This feature requires gcc version 4.2 or above, or a distribution
669 gcc with the feature backported. Older versions are automatically
670 detected and for those versions, this configuration option is ignored.
672 config CC_STACKPROTECTOR_ALL
673 bool "Use stack-protector for all functions"
674 depends on CC_STACKPROTECTOR
676 Normally, GCC only inserts the canary value protection for
677 functions that use large-ish on-stack buffers. By enabling
678 this option, GCC will be asked to do this for ALL functions.
680 source kernel/Kconfig.hz
684 depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
689 # Use the generic interrupt handling code in kernel/irq/:
691 config GENERIC_HARDIRQS
695 config GENERIC_IRQ_PROBE
699 # we have no ISA slots, but we do have ISA-style DMA.
704 config GENERIC_PENDING_IRQ
706 depends on GENERIC_HARDIRQS && SMP
709 menu "Power management options"
711 source kernel/power/Kconfig
713 source "drivers/acpi/Kconfig"
715 source "arch/x86_64/kernel/cpufreq/Kconfig"
719 menu "Bus options (PCI etc.)"
723 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
725 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
732 bool "Support mmconfig PCI config space access"
733 depends on PCI && ACPI
735 source "drivers/pci/pcie/Kconfig"
737 source "drivers/pci/Kconfig"
739 source "drivers/pcmcia/Kconfig"
741 source "drivers/pci/hotplug/Kconfig"
746 menu "Executable file formats / Emulations"
748 source "fs/Kconfig.binfmt"
750 config IA32_EMULATION
751 bool "IA32 Emulation"
753 Include code to run 32-bit programs under a 64-bit kernel. You should likely
754 turn this on, unless you're 100% sure that you don't have any 32-bit programs
758 tristate "IA32 a.out support"
759 depends on IA32_EMULATION
761 Support old a.out binaries in the 32bit emulation.
765 depends on IA32_EMULATION
768 config COMPAT_FOR_U64_ALIGNMENT
771 config SYSVIPC_COMPAT
773 depends on COMPAT && SYSVIPC
780 source drivers/Kconfig
782 source "drivers/firmware/Kconfig"
786 menu "Instrumentation Support"
787 depends on EXPERIMENTAL
789 source "arch/x86_64/oprofile/Kconfig"
793 depends on KALLSYMS && MODULES
795 Kprobes allows you to trap at almost any kernel address and
796 execute a callback function. register_kprobe() establishes
797 a probepoint and specifies the callback. Kprobes is useful
798 for kernel debugging, non-intrusive instrumentation and testing.
799 If in doubt, say "N".
802 source "arch/x86_64/Kconfig.debug"
804 source "security/Kconfig"
806 source "crypto/Kconfig"