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 LOCKDEP_SUPPORT
35 config STACKTRACE_SUPPORT
39 config SEMAPHORE_SLEEPERS
53 config RWSEM_GENERIC_SPINLOCK
57 config RWSEM_XCHGADD_ALGORITHM
60 config GENERIC_HWEIGHT
64 config GENERIC_CALIBRATE_DELAY
76 config GENERIC_ISA_DMA
84 config ARCH_MAY_HAVE_PC_FDC
88 config ARCH_POPULATES_NODE_MAP
104 config ARCH_HAS_ILOG2_U32
108 config ARCH_HAS_ILOG2_U64
112 source "init/Kconfig"
115 menu "Processor type and features"
118 prompt "Subarchitecture Type"
124 Choose this option if your computer is a standard PC or compatible.
127 bool "Support for ScaleMP vSMP"
130 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
131 supposed to run on these EM64T-based machines. Only choose this option
132 if you have one of these machines.
137 prompt "Processor family"
141 bool "AMD-Opteron/Athlon64"
143 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
146 bool "Intel P4 / older Netburst based Xeon"
148 Optimize for Intel Pentium 4 and older Nocona/Dempsey Xeon CPUs
149 with Intel Extended Memory 64 Technology(EM64T). For details see
150 <http://www.intel.com/technology/64bitextensions/>.
151 Note the the latest Xeons (Xeon 51xx and 53xx) are not based on the
152 Netburst core and shouldn't use this option. You can distingush them
153 using the cpu family field
154 in /proc/cpuinfo. Family 15 is a older Xeon, Family 6 a newer one
155 (this rule only applies to system that support EM64T)
158 bool "Intel Core2 / newer Xeon"
160 Optimize for Intel Core2 and newer Xeons (51xx)
161 You can distingush the newer Xeons from the older ones using
162 the cpu family field in /proc/cpuinfo. 15 is a older Xeon
163 (use CONFIG_MPSC then), 6 is a newer one. This rule only
164 applies to CPUs that support EM64T.
167 bool "Generic-x86-64"
170 Run equally well on all x86-64 CPUs.
175 # Define implied options from the CPU selection here
177 config X86_L1_CACHE_BYTES
179 default "128" if GENERIC_CPU || MPSC
180 default "64" if MK8 || MCORE2
182 config X86_L1_CACHE_SHIFT
184 default "7" if GENERIC_CPU || MPSC
185 default "6" if MK8 || MCORE2
187 config X86_INTERNODE_CACHE_BYTES
189 default "4096" if X86_VSMP
190 default X86_L1_CACHE_BYTES if !X86_VSMP
201 tristate "/dev/cpu/microcode - Intel CPU microcode support"
204 If you say Y here the 'File systems' section, you will be
205 able to update the microcode on Intel processors. You will
206 obviously need the actual microcode binary data itself which is
207 not shipped with the Linux kernel.
209 For latest news and information on obtaining all the required
210 ingredients for this driver, check:
211 <http://www.urbanmyth.org/microcode/>.
213 To compile this driver as a module, choose M here: the
214 module will be called microcode.
215 If you use modprobe or kmod you may also want to add the line
216 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
218 config MICROCODE_OLD_INTERFACE
224 tristate "/dev/cpu/*/msr - Model-specific register support"
226 This device gives privileged processes access to the x86
227 Model-Specific Registers (MSRs). It is a character device with
228 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
229 MSR accesses are directed to a specific CPU on multi-processor
233 tristate "/dev/cpu/*/cpuid - CPU information support"
235 This device gives processes access to the x86 CPUID instruction to
236 be executed on a specific processor. It is a character device
237 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
242 depends on SMP && !MK8
245 config MATH_EMULATION
258 config X86_LOCAL_APIC
263 bool "MTRR (Memory Type Range Register) support"
265 On Intel P6 family processors (Pentium Pro, Pentium II and later)
266 the Memory Type Range Registers (MTRRs) may be used to control
267 processor access to memory ranges. This is most useful if you have
268 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
269 allows bus write transfers to be combined into a larger transfer
270 before bursting over the PCI/AGP bus. This can increase performance
271 of image write operations 2.5 times or more. Saying Y here creates a
272 /proc/mtrr file which may be used to manipulate your processor's
273 MTRRs. Typically the X server should use this.
275 This code has a reasonably generic interface so that similar
276 control registers on other processors can be easily supported
279 Saying Y here also fixes a problem with buggy SMP BIOSes which only
280 set the MTRRs for the boot CPU and not for the secondary CPUs. This
281 can lead to all sorts of problems, so it's good to say Y here.
283 Just say Y here, all x86-64 machines support MTRRs.
285 See <file:Documentation/mtrr.txt> for more information.
288 bool "Symmetric multi-processing support"
290 This enables support for systems with more than one CPU. If you have
291 a system with only one CPU, like most personal computers, say N. If
292 you have a system with more than one CPU, say Y.
294 If you say N here, the kernel will run on single and multiprocessor
295 machines, but will use only one CPU of a multiprocessor machine. If
296 you say Y here, the kernel will run on many, but not all,
297 singleprocessor machines. On a singleprocessor machine, the kernel
298 will run faster if you say N here.
300 If you don't know what to do here, say N.
303 bool "SMT (Hyperthreading) scheduler support"
307 SMT scheduler support improves the CPU scheduler's decision making
308 when dealing with Intel Pentium 4 chips with HyperThreading at a
309 cost of slightly increased overhead in some places. If unsure say
313 bool "Multi-core scheduler support"
317 Multi-core scheduler support improves the CPU scheduler's decision
318 making when dealing with multi-core CPU chips at a cost of slightly
319 increased overhead in some places. If unsure say N here.
321 source "kernel/Kconfig.preempt"
324 bool "Non Uniform Memory Access (NUMA) Support"
327 Enable NUMA (Non Uniform Memory Access) support. The kernel
328 will try to allocate memory used by a CPU on the local memory
329 controller of the CPU and add some more NUMA awareness to the kernel.
330 This code is recommended on all multiprocessor Opteron systems.
331 If the system is EM64T, you should say N unless your system is EM64T
335 bool "Old style AMD Opteron NUMA detection"
336 depends on NUMA && PCI
339 Enable K8 NUMA node topology detection. You should say Y here if
340 you have a multi processor AMD K8 system. This uses an old
341 method to read the NUMA configuration directly from the builtin
342 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
343 instead, which also takes priority if both are compiled in.
348 depends on NEED_MULTIPLE_NODES
350 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
352 config X86_64_ACPI_NUMA
353 bool "ACPI NUMA detection"
360 Enable ACPI SRAT based node topology detection.
363 bool "NUMA emulation"
366 Enable NUMA emulation. A flat machine will be split
367 into virtual nodes when booted with "numa=fake=N", where N is the
368 number of nodes. This is only useful for debugging.
370 config ARCH_DISCONTIGMEM_ENABLE
375 config ARCH_DISCONTIGMEM_DEFAULT
379 config ARCH_SPARSEMEM_ENABLE
381 depends on (NUMA || EXPERIMENTAL)
383 config ARCH_MEMORY_PROBE
385 depends on MEMORY_HOTPLUG
387 config ARCH_FLATMEM_ENABLE
393 config MEMORY_HOTPLUG_RESERVE
395 depends on (MEMORY_HOTPLUG && DISCONTIGMEM)
397 config HAVE_ARCH_EARLY_PFN_TO_NID
401 config OUT_OF_LINE_PFN_TO_PAGE
403 depends on DISCONTIGMEM
406 int "Maximum number of CPUs (2-256)"
411 This allows you to specify the maximum number of CPUs which this
412 kernel will support. Current maximum is 256 CPUs due to
413 APIC addressing limits. Less depending on the hardware.
415 This is purely to save memory - each supported CPU requires
416 memory in the static kernel configuration.
419 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
420 depends on SMP && HOTPLUG && EXPERIMENTAL
422 Say Y here to experiment with turning CPUs off and on. CPUs
423 can be controlled through /sys/devices/system/cpu/cpu#.
424 Say N if you want to disable CPU hotplug.
426 config ARCH_ENABLE_MEMORY_HOTPLUG
433 Use the IA-PC HPET (High Precision Event Timer) to manage
434 time in preference to the PIT and RTC, if a HPET is
435 present. The HPET provides a stable time base on SMP
436 systems, unlike the TSC, but it is more expensive to access,
437 as it is off-chip. You can find the HPET spec at
438 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
440 config HPET_EMULATE_RTC
441 bool "Provide RTC interrupt"
442 depends on HPET_TIMER && RTC=y
444 # Mark as embedded because too many people got it wrong.
445 # The code disables itself when not needed.
447 bool "IOMMU support" if EMBEDDED
453 Support for full DMA access of devices with 32bit memory access only
454 on systems with more than 3GB. This is usually needed for USB,
455 sound, many IDE/SATA chipsets and some other devices.
456 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
457 based IOMMU and a software bounce buffer based IOMMU used on Intel
458 systems and as fallback.
459 The code is only active when needed (enough memory and limited
460 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
464 bool "IBM Calgary IOMMU support"
466 depends on PCI && EXPERIMENTAL
468 Support for hardware IOMMUs in IBM's xSeries x366 and x460
469 systems. Needed to run systems with more than 3GB of memory
470 properly with 32-bit PCI devices that do not support DAC
471 (Double Address Cycle). Calgary also supports bus level
472 isolation, where all DMAs pass through the IOMMU. This
473 prevents them from going anywhere except their intended
474 destination. This catches hard-to-find kernel bugs and
475 mis-behaving drivers and devices that do not use the DMA-API
476 properly to set up their DMA buffers. The IOMMU can be
477 turned off at boot time with the iommu=off parameter.
478 Normally the kernel will make the right choice by itself.
481 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
482 bool "Should Calgary be enabled by default?"
484 depends on CALGARY_IOMMU
486 Should Calgary be enabled by default? if you choose 'y', Calgary
487 will be used (if it exists). If you choose 'n', Calgary will not be
488 used even if it exists. If you choose 'n' and would like to use
489 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
492 # need this always selected by IOMMU for the VIA workaround
497 bool "Machine check support" if EMBEDDED
500 Include a machine check error handler to report hardware errors.
501 This version will require the mcelog utility to decode some
502 machine check error logs. See
503 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
506 bool "Intel MCE features"
507 depends on X86_MCE && X86_LOCAL_APIC
510 Additional support for intel specific MCE features such as
514 bool "AMD MCE features"
515 depends on X86_MCE && X86_LOCAL_APIC
518 Additional support for AMD specific MCE features such as
519 the DRAM Error Threshold.
522 bool "kexec system call"
524 kexec is a system call that implements the ability to shutdown your
525 current kernel, and to start another kernel. It is like a reboot
526 but it is independent of the system firmware. And like a reboot
527 you can start any kernel with it, not just Linux.
529 The name comes from the similarity to the exec system call.
531 It is an ongoing process to be certain the hardware in a machine
532 is properly shutdown, so do not be surprised if this code does not
533 initially work for you. It may help to enable device hotplugging
534 support. As of this writing the exact hardware interface is
535 strongly in flux, so no good recommendation can be made.
538 bool "kernel crash dumps (EXPERIMENTAL)"
539 depends on EXPERIMENTAL
541 Generate crash dump after being started by kexec.
542 This should be normally only set in special crash dump kernels
543 which are loaded in the main kernel with kexec-tools into
544 a specially reserved region and then later executed after
545 a crash by kdump/kexec. The crash dump kernel must be compiled
546 to a memory address not used by the main kernel or BIOS using
548 For more details see Documentation/kdump/kdump.txt
550 config PHYSICAL_START
551 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
552 default "0x1000000" if CRASH_DUMP
555 This gives the physical address where the kernel is loaded. Normally
556 for regular kernels this value is 0x200000 (2MB). But in the case
557 of kexec on panic the fail safe kernel needs to run at a different
558 address than the panic-ed kernel. This option is used to set the load
559 address for kernels used to capture crash dump on being kexec'ed
560 after panic. The default value for crash dump kernels is
561 0x1000000 (16MB). This can also be set based on the "X" value as
562 specified in the "crashkernel=YM@XM" command line boot parameter
563 passed to the panic-ed kernel. Typically this parameter is set as
564 crashkernel=64M@16M. Please take a look at
565 Documentation/kdump/kdump.txt for more details about crash dumps.
567 Don't change this unless you know what you are doing.
570 bool "Enable seccomp to safely compute untrusted bytecode"
574 This kernel feature is useful for number crunching applications
575 that may need to compute untrusted bytecode during their
576 execution. By using pipes or other transports made available to
577 the process as file descriptors supporting the read/write
578 syscalls, it's possible to isolate those applications in
579 their own address space using seccomp. Once seccomp is
580 enabled via /proc/<pid>/seccomp, it cannot be disabled
581 and the task is only allowed to execute a few safe syscalls
582 defined by each seccomp mode.
584 If unsure, say Y. Only embedded should say N here.
586 config CC_STACKPROTECTOR
587 bool "Enable -fstack-protector buffer overflow detection (EXPRIMENTAL)"
588 depends on EXPERIMENTAL
590 This option turns on the -fstack-protector GCC feature. This
591 feature puts, at the beginning of critical functions, a canary
592 value on the stack just before the return address, and validates
593 the value just before actually returning. Stack based buffer
594 overflows (that need to overwrite this return address) now also
595 overwrite the canary, which gets detected and the attack is then
596 neutralized via a kernel panic.
598 This feature requires gcc version 4.2 or above, or a distribution
599 gcc with the feature backported. Older versions are automatically
600 detected and for those versions, this configuration option is ignored.
602 config CC_STACKPROTECTOR_ALL
603 bool "Use stack-protector for all functions"
604 depends on CC_STACKPROTECTOR
606 Normally, GCC only inserts the canary value protection for
607 functions that use large-ish on-stack buffers. By enabling
608 this option, GCC will be asked to do this for ALL functions.
610 source kernel/Kconfig.hz
613 bool "Function reordering"
616 This option enables the toolchain to reorder functions for a more
617 optimal TLB usage. If you have pretty much any version of binutils,
618 this can increase your kernel build time by roughly one minute.
622 depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
627 # Use the generic interrupt handling code in kernel/irq/:
629 config GENERIC_HARDIRQS
633 config GENERIC_IRQ_PROBE
637 # we have no ISA slots, but we do have ISA-style DMA.
642 config GENERIC_PENDING_IRQ
644 depends on GENERIC_HARDIRQS && SMP
647 menu "Power management options"
649 source kernel/power/Kconfig
651 source "drivers/acpi/Kconfig"
653 source "arch/x86_64/kernel/cpufreq/Kconfig"
657 menu "Bus options (PCI etc.)"
662 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
669 bool "Support mmconfig PCI config space access"
670 depends on PCI && ACPI
672 source "drivers/pci/pcie/Kconfig"
674 source "drivers/pci/Kconfig"
676 source "drivers/pcmcia/Kconfig"
678 source "drivers/pci/hotplug/Kconfig"
683 menu "Executable file formats / Emulations"
685 source "fs/Kconfig.binfmt"
687 config IA32_EMULATION
688 bool "IA32 Emulation"
690 Include code to run 32-bit programs under a 64-bit kernel. You should likely
691 turn this on, unless you're 100% sure that you don't have any 32-bit programs
695 tristate "IA32 a.out support"
696 depends on IA32_EMULATION
698 Support old a.out binaries in the 32bit emulation.
702 depends on IA32_EMULATION
705 config SYSVIPC_COMPAT
707 depends on COMPAT && SYSVIPC
714 source drivers/Kconfig
716 source "drivers/firmware/Kconfig"
720 menu "Instrumentation Support"
721 depends on EXPERIMENTAL
723 source "arch/x86_64/oprofile/Kconfig"
726 bool "Kprobes (EXPERIMENTAL)"
727 depends on KALLSYMS && EXPERIMENTAL && MODULES
729 Kprobes allows you to trap at almost any kernel address and
730 execute a callback function. register_kprobe() establishes
731 a probepoint and specifies the callback. Kprobes is useful
732 for kernel debugging, non-intrusive instrumentation and testing.
733 If in doubt, say "N".
736 source "arch/x86_64/Kconfig.debug"
738 source "security/Kconfig"
740 source "crypto/Kconfig"