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/>.
27 config LOCKDEP_SUPPORT
31 config STACKTRACE_SUPPORT
33 depends on !X86_64_XEN
36 config SEMAPHORE_SLEEPERS
50 config RWSEM_GENERIC_SPINLOCK
54 config RWSEM_XCHGADD_ALGORITHM
57 config GENERIC_HWEIGHT
61 config GENERIC_CALIBRATE_DELAY
73 config GENERIC_ISA_DMA
81 config ARCH_MAY_HAVE_PC_FDC
96 menu "Processor type and features"
99 prompt "Subarchitecture Type"
105 Choose this option if your computer is a standard PC or compatible.
108 bool "Support for ScaleMP vSMP"
110 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
111 supposed to run on these EM64T-based machines. Only choose this option
112 if you have one of these machines.
117 prompt "Processor family"
121 bool "AMD-Opteron/Athlon64"
123 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
128 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
129 Extended Memory 64 Technology(EM64T). For details see
130 <http://www.intel.com/technology/64bitextensions/>.
133 bool "Generic-x86-64"
140 bool "Enable Xen compatible kernel"
143 This option will compile a kernel compatible with Xen hypervisor
147 depends on X86_64_XEN
152 depends on X86_64_XEN
156 # Define implied options from the CPU selection here
158 config X86_L1_CACHE_BYTES
160 default "128" if GENERIC_CPU || MPSC
163 config X86_L1_CACHE_SHIFT
165 default "7" if GENERIC_CPU || MPSC
168 config X86_INTERNODE_CACHE_BYTES
170 default "4096" if X86_VSMP
171 default X86_L1_CACHE_BYTES if !X86_VSMP
175 depends on !X86_64_XEN
183 tristate "/dev/cpu/microcode - Intel CPU microcode support"
185 If you say Y here the 'File systems' section, you will be
186 able to update the microcode on Intel processors. You will
187 obviously need the actual microcode binary data itself which is
188 not shipped with the Linux kernel.
190 For latest news and information on obtaining all the required
191 ingredients for this driver, check:
192 <http://www.urbanmyth.org/microcode/>.
194 To compile this driver as a module, choose M here: the
195 module will be called microcode.
196 If you use modprobe or kmod you may also want to add the line
197 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
200 tristate "/dev/cpu/*/msr - Model-specific register support"
202 This device gives privileged processes access to the x86
203 Model-Specific Registers (MSRs). It is a character device with
204 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
205 MSR accesses are directed to a specific CPU on multi-processor
209 tristate "/dev/cpu/*/cpuid - CPU information support"
211 This device gives processes access to the x86 CPUID instruction to
212 be executed on a specific processor. It is a character device
213 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
218 depends on SMP && !MK8 && !X86_64_XEN
221 config MATH_EMULATION
232 depends !XEN_UNPRIVILEGED_GUEST
235 config X86_XEN_GENAPIC
238 default XEN_PRIVILEGED_GUEST || SMP
240 config X86_LOCAL_APIC
242 depends !XEN_UNPRIVILEGED_GUEST
246 bool "MTRR (Memory Type Range Register) support"
247 depends on !XEN_UNPRIVILEGED_GUEST
249 On Intel P6 family processors (Pentium Pro, Pentium II and later)
250 the Memory Type Range Registers (MTRRs) may be used to control
251 processor access to memory ranges. This is most useful if you have
252 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
253 allows bus write transfers to be combined into a larger transfer
254 before bursting over the PCI/AGP bus. This can increase performance
255 of image write operations 2.5 times or more. Saying Y here creates a
256 /proc/mtrr file which may be used to manipulate your processor's
257 MTRRs. Typically the X server should use this.
259 This code has a reasonably generic interface so that similar
260 control registers on other processors can be easily supported
263 Saying Y here also fixes a problem with buggy SMP BIOSes which only
264 set the MTRRs for the boot CPU and not for the secondary CPUs. This
265 can lead to all sorts of problems, so it's good to say Y here.
267 Just say Y here, all x86-64 machines support MTRRs.
269 See <file:Documentation/mtrr.txt> for more information.
272 bool "Symmetric multi-processing support"
274 This enables support for systems with more than one CPU. If you have
275 a system with only one CPU, like most personal computers, say N. If
276 you have a system with more than one CPU, say Y.
278 If you say N here, the kernel will run on single and multiprocessor
279 machines, but will use only one CPU of a multiprocessor machine. If
280 you say Y here, the kernel will run on many, but not all,
281 singleprocessor machines. On a singleprocessor machine, the kernel
282 will run faster if you say N here.
284 If you don't know what to do here, say N.
287 bool "SMT (Hyperthreading) scheduler support"
288 depends on SMP && !X86_64_XEN
291 SMT scheduler support improves the CPU scheduler's decision making
292 when dealing with Intel Pentium 4 chips with HyperThreading at a
293 cost of slightly increased overhead in some places. If unsure say
297 bool "Multi-core scheduler support"
298 depends on SMP && !X86_64_XEN
301 Multi-core scheduler support improves the CPU scheduler's decision
302 making when dealing with multi-core CPU chips at a cost of slightly
303 increased overhead in some places. If unsure say N here.
305 source "kernel/Kconfig.preempt"
308 bool "Non Uniform Memory Access (NUMA) Support"
309 depends on SMP && !X86_64_XEN
311 Enable NUMA (Non Uniform Memory Access) support. The kernel
312 will try to allocate memory used by a CPU on the local memory
313 controller of the CPU and add some more NUMA awareness to the kernel.
314 This code is recommended on all multiprocessor Opteron systems.
315 If the system is EM64T, you should say N unless your system is EM64T
319 bool "Old style AMD Opteron NUMA detection"
323 Enable K8 NUMA node topology detection. You should say Y here if
324 you have a multi processor AMD K8 system. This uses an old
325 method to read the NUMA configurtion directly from the builtin
326 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
327 instead, which also takes priority if both are compiled in.
332 depends on NEED_MULTIPLE_NODES
334 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
336 config X86_64_ACPI_NUMA
337 bool "ACPI NUMA detection"
344 Enable ACPI SRAT based node topology detection.
347 bool "NUMA emulation"
350 Enable NUMA emulation. A flat machine will be split
351 into virtual nodes when booted with "numa=fake=N", where N is the
352 number of nodes. This is only useful for debugging.
354 config ARCH_DISCONTIGMEM_ENABLE
360 config ARCH_DISCONTIGMEM_ENABLE
364 config ARCH_DISCONTIGMEM_DEFAULT
368 config ARCH_SPARSEMEM_ENABLE
370 depends on (NUMA || EXPERIMENTAL) && !X86_64_XEN
372 config ARCH_MEMORY_PROBE
374 depends on MEMORY_HOTPLUG
376 config ARCH_FLATMEM_ENABLE
382 config HAVE_ARCH_EARLY_PFN_TO_NID
386 config OUT_OF_LINE_PFN_TO_PAGE
388 depends on DISCONTIGMEM
391 int "Maximum number of CPUs (2-256)"
394 default "16" if X86_64_XEN
397 This allows you to specify the maximum number of CPUs which this
398 kernel will support. Current maximum is 256 CPUs due to
399 APIC addressing limits. Less depending on the hardware.
401 This is purely to save memory - each supported CPU requires
402 memory in the static kernel configuration.
405 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
406 depends on SMP && HOTPLUG && EXPERIMENTAL
408 Say Y here to experiment with turning CPUs off and on. CPUs
409 can be controlled through /sys/devices/system/cpu/cpu#.
410 Say N if you want to disable CPU hotplug.
412 config ARCH_ENABLE_MEMORY_HOTPLUG
417 depends on !X86_64_XEN
420 Use the IA-PC HPET (High Precision Event Timer) to manage
421 time in preference to the PIT and RTC, if a HPET is
422 present. The HPET provides a stable time base on SMP
423 systems, unlike the TSC, but it is more expensive to access,
424 as it is off-chip. You can find the HPET spec at
425 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
427 config HPET_EMULATE_RTC
428 bool "Provide RTC interrupt"
429 depends on HPET_TIMER && RTC=y
431 # Mark as embedded because too many people got it wrong.
432 # The code disables itself when not needed.
434 bool "IOMMU support" if EMBEDDED
438 depends on PCI && !X86_64_XEN
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 IOMMU and a software bounce buffer based IOMMU used on Intel
445 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"
454 depends on PCI && EXPERIMENTAL
456 Support for hardware IOMMUs in IBM's xSeries x366 and x460
457 systems. Needed to run systems with more than 3GB of memory
458 properly with 32-bit PCI devices that do not support DAC
459 (Double Address Cycle). Calgary also supports bus level
460 isolation, where all DMAs pass through the IOMMU. This
461 prevents them from going anywhere except their intended
462 destination. This catches hard-to-find kernel bugs and
463 mis-behaving drivers and devices that do not use the DMA-API
464 properly to set up their DMA buffers. The IOMMU can be
465 turned off at boot time with the iommu=off parameter.
466 Normally the kernel will make the right choice by itself.
469 # need this always selected by IOMMU for the VIA workaround
474 bool "Machine check support" if EMBEDDED
475 depends on !X86_64_XEN
478 Include a machine check error handler to report hardware errors.
479 This version will require the mcelog utility to decode some
480 machine check error logs. See
481 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
484 bool "Intel MCE features"
485 depends on X86_MCE && X86_LOCAL_APIC
488 Additional support for intel specific MCE features such as
492 bool "AMD MCE features"
493 depends on X86_MCE && X86_LOCAL_APIC
496 Additional support for AMD specific MCE features such as
497 the DRAM Error Threshold.
500 bool "kexec system call (EXPERIMENTAL)"
501 depends on EXPERIMENTAL && !X86_64_XEN
503 kexec is a system call that implements the ability to shutdown your
504 current kernel, and to start another kernel. It is like a reboot
505 but it is independent of the system firmware. And like a reboot
506 you can start any kernel with it, not just Linux.
508 The name comes from the similarity to the exec system call.
510 It is an ongoing process to be certain the hardware in a machine
511 is properly shutdown, so do not be surprised if this code does not
512 initially work for you. It may help to enable device hotplugging
513 support. As of this writing the exact hardware interface is
514 strongly in flux, so no good recommendation can be made.
517 bool "kernel crash dumps (EXPERIMENTAL)"
518 depends on EXPERIMENTAL
520 Generate crash dump after being started by kexec.
522 config PHYSICAL_START
523 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
524 default "0x1000000" if CRASH_DUMP
527 This gives the physical address where the kernel is loaded. Normally
528 for regular kernels this value is 0x200000 (2MB). But in the case
529 of kexec on panic the fail safe kernel needs to run at a different
530 address than the panic-ed kernel. This option is used to set the load
531 address for kernels used to capture crash dump on being kexec'ed
532 after panic. The default value for crash dump kernels is
533 0x1000000 (16MB). This can also be set based on the "X" value as
534 specified in the "crashkernel=YM@XM" command line boot parameter
535 passed to the panic-ed kernel. Typically this parameter is set as
536 crashkernel=64M@16M. Please take a look at
537 Documentation/kdump/kdump.txt for more details about crash dumps.
539 Don't change this unless you know what you are doing.
542 bool "Enable seccomp to safely compute untrusted bytecode"
546 This kernel feature is useful for number crunching applications
547 that may need to compute untrusted bytecode during their
548 execution. By using pipes or other transports made available to
549 the process as file descriptors supporting the read/write
550 syscalls, it's possible to isolate those applications in
551 their own address space using seccomp. Once seccomp is
552 enabled via /proc/<pid>/seccomp, it cannot be disabled
553 and the task is only allowed to execute a few safe syscalls
554 defined by each seccomp mode.
556 If unsure, say Y. Only embedded should say N here.
558 source kernel/Kconfig.hz
561 bool "Function reordering"
564 This option enables the toolchain to reorder functions for a more
565 optimal TLB usage. If you have pretty much any version of binutils,
566 this can increase your kernel build time by roughly one minute.
570 depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
575 # Use the generic interrupt handling code in kernel/irq/:
577 config GENERIC_HARDIRQS
581 config GENERIC_IRQ_PROBE
585 # we have no ISA slots, but we do have ISA-style DMA.
590 config GENERIC_PENDING_IRQ
592 depends on GENERIC_HARDIRQS && SMP
595 menu "Power management options"
596 depends on !XEN_UNPRIVILEGED_GUEST
599 source kernel/power/Kconfig
602 source "drivers/acpi/Kconfig"
604 source "arch/x86_64/kernel/cpufreq/Kconfig"
608 menu "Bus options (PCI etc.)"
613 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
620 bool "Support mmconfig PCI config space access"
621 depends on PCI && ACPI
623 config XEN_PCIDEV_FRONTEND
624 bool "Xen PCI Frontend"
625 depends on PCI && X86_64_XEN
628 The PCI device frontend driver allows the kernel to import arbitrary
629 PCI devices from a PCI backend to support PCI driver domains.
631 config XEN_PCIDEV_FE_DEBUG
632 bool "Xen PCI Frontend Debugging"
633 depends on XEN_PCIDEV_FRONTEND
636 Enables some debug statements within the PCI Frontend.
638 source "drivers/pci/pcie/Kconfig"
640 source "drivers/pci/Kconfig"
642 source "drivers/pcmcia/Kconfig"
644 source "drivers/pci/hotplug/Kconfig"
649 menu "Executable file formats / Emulations"
651 source "fs/Kconfig.binfmt"
653 config IA32_EMULATION
654 bool "IA32 Emulation"
656 Include code to run 32-bit programs under a 64-bit kernel. You should likely
657 turn this on, unless you're 100% sure that you don't have any 32-bit programs
661 tristate "IA32 a.out support"
662 depends on IA32_EMULATION
664 Support old a.out binaries in the 32bit emulation.
668 depends on IA32_EMULATION
671 config SYSVIPC_COMPAT
673 depends on COMPAT && SYSVIPC
680 source drivers/Kconfig
682 source "drivers/firmware/Kconfig"
686 menu "Instrumentation Support"
687 depends on EXPERIMENTAL
689 source "arch/x86_64/oprofile/Kconfig"
692 bool "Kprobes (EXPERIMENTAL)"
693 depends on EXPERIMENTAL && MODULES
695 Kprobes allows you to trap at almost any kernel address and
696 execute a callback function. register_kprobe() establishes
697 a probepoint and specifies the callback. Kprobes is useful
698 for kernel debugging, non-intrusive instrumentation and testing.
699 If in doubt, say "N".
702 source "arch/x86_64/Kconfig.debug"
704 source "kernel/vserver/Kconfig"
706 source "security/Kconfig"
708 source "crypto/Kconfig"
710 source "drivers/xen/Kconfig"