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 STACKTRACE_SUPPORT
31 config SEMAPHORE_SLEEPERS
45 config RWSEM_GENERIC_SPINLOCK
49 config RWSEM_XCHGADD_ALGORITHM
52 config GENERIC_HWEIGHT
56 config GENERIC_CALIBRATE_DELAY
68 config GENERIC_ISA_DMA
76 config ARCH_MAY_HAVE_PC_FDC
87 menu "Processor type and features"
90 prompt "Subarchitecture Type"
96 Choose this option if your computer is a standard PC or compatible.
99 bool "Support for ScaleMP vSMP"
101 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
102 supposed to run on these EM64T-based machines. Only choose this option
103 if you have one of these machines.
108 prompt "Processor family"
112 bool "AMD-Opteron/Athlon64"
114 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
119 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
120 Extended Memory 64 Technology(EM64T). For details see
121 <http://www.intel.com/technology/64bitextensions/>.
124 bool "Generic-x86-64"
131 # Define implied options from the CPU selection here
133 config X86_L1_CACHE_BYTES
135 default "128" if GENERIC_CPU || MPSC
138 config X86_L1_CACHE_SHIFT
140 default "7" if GENERIC_CPU || MPSC
143 config X86_INTERNODE_CACHE_BYTES
145 default "4096" if X86_VSMP
146 default X86_L1_CACHE_BYTES if !X86_VSMP
157 tristate "/dev/cpu/microcode - Intel CPU microcode support"
159 If you say Y here the 'File systems' section, you will be
160 able to update the microcode on Intel processors. You will
161 obviously need the actual microcode binary data itself which is
162 not shipped with the Linux kernel.
164 For latest news and information on obtaining all the required
165 ingredients for this driver, check:
166 <http://www.urbanmyth.org/microcode/>.
168 To compile this driver as a module, choose M here: the
169 module will be called microcode.
170 If you use modprobe or kmod you may also want to add the line
171 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
174 tristate "/dev/cpu/*/msr - Model-specific register support"
176 This device gives privileged processes access to the x86
177 Model-Specific Registers (MSRs). It is a character device with
178 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
179 MSR accesses are directed to a specific CPU on multi-processor
183 tristate "/dev/cpu/*/cpuid - CPU information support"
185 This device gives processes access to the x86 CPUID instruction to
186 be executed on a specific processor. It is a character device
187 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
192 depends on SMP && !MK8
195 config MATH_EMULATION
208 config X86_LOCAL_APIC
213 bool "MTRR (Memory Type Range Register) support"
215 On Intel P6 family processors (Pentium Pro, Pentium II and later)
216 the Memory Type Range Registers (MTRRs) may be used to control
217 processor access to memory ranges. This is most useful if you have
218 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
219 allows bus write transfers to be combined into a larger transfer
220 before bursting over the PCI/AGP bus. This can increase performance
221 of image write operations 2.5 times or more. Saying Y here creates a
222 /proc/mtrr file which may be used to manipulate your processor's
223 MTRRs. Typically the X server should use this.
225 This code has a reasonably generic interface so that similar
226 control registers on other processors can be easily supported
229 Saying Y here also fixes a problem with buggy SMP BIOSes which only
230 set the MTRRs for the boot CPU and not for the secondary CPUs. This
231 can lead to all sorts of problems, so it's good to say Y here.
233 Just say Y here, all x86-64 machines support MTRRs.
235 See <file:Documentation/mtrr.txt> for more information.
238 bool "Symmetric multi-processing support"
240 This enables support for systems with more than one CPU. If you have
241 a system with only one CPU, like most personal computers, say N. If
242 you have a system with more than one CPU, say Y.
244 If you say N here, the kernel will run on single and multiprocessor
245 machines, but will use only one CPU of a multiprocessor machine. If
246 you say Y here, the kernel will run on many, but not all,
247 singleprocessor machines. On a singleprocessor machine, the kernel
248 will run faster if you say N here.
250 If you don't know what to do here, say N.
253 bool "SMT (Hyperthreading) scheduler support"
257 SMT scheduler support improves the CPU scheduler's decision making
258 when dealing with Intel Pentium 4 chips with HyperThreading at a
259 cost of slightly increased overhead in some places. If unsure say
263 bool "Multi-core scheduler support"
267 Multi-core scheduler support improves the CPU scheduler's decision
268 making when dealing with multi-core CPU chips at a cost of slightly
269 increased overhead in some places. If unsure say N here.
271 source "kernel/Kconfig.preempt"
274 bool "Non Uniform Memory Access (NUMA) Support"
277 Enable NUMA (Non Uniform Memory Access) support. The kernel
278 will try to allocate memory used by a CPU on the local memory
279 controller of the CPU and add some more NUMA awareness to the kernel.
280 This code is recommended on all multiprocessor Opteron systems.
281 If the system is EM64T, you should say N unless your system is EM64T
285 bool "Old style AMD Opteron NUMA detection"
289 Enable K8 NUMA node topology detection. You should say Y here if
290 you have a multi processor AMD K8 system. This uses an old
291 method to read the NUMA configurtion directly from the builtin
292 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
293 instead, which also takes priority if both are compiled in.
298 depends on NEED_MULTIPLE_NODES
300 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
302 config X86_64_ACPI_NUMA
303 bool "ACPI NUMA detection"
310 Enable ACPI SRAT based node topology detection.
313 bool "NUMA emulation"
316 Enable NUMA emulation. A flat machine will be split
317 into virtual nodes when booted with "numa=fake=N", where N is the
318 number of nodes. This is only useful for debugging.
320 config ARCH_DISCONTIGMEM_ENABLE
326 config ARCH_DISCONTIGMEM_ENABLE
330 config ARCH_DISCONTIGMEM_DEFAULT
334 config ARCH_SPARSEMEM_ENABLE
336 depends on (NUMA || EXPERIMENTAL)
338 config ARCH_MEMORY_PROBE
340 depends on MEMORY_HOTPLUG
342 config ARCH_FLATMEM_ENABLE
348 config HAVE_ARCH_EARLY_PFN_TO_NID
352 config OUT_OF_LINE_PFN_TO_PAGE
354 depends on DISCONTIGMEM
357 int "Maximum number of CPUs (2-256)"
362 This allows you to specify the maximum number of CPUs which this
363 kernel will support. Current maximum is 256 CPUs due to
364 APIC addressing limits. Less depending on the hardware.
366 This is purely to save memory - each supported CPU requires
367 memory in the static kernel configuration.
370 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
371 depends on SMP && HOTPLUG && EXPERIMENTAL
373 Say Y here to experiment with turning CPUs off and on. CPUs
374 can be controlled through /sys/devices/system/cpu/cpu#.
375 Say N if you want to disable CPU hotplug.
377 config ARCH_ENABLE_MEMORY_HOTPLUG
384 Use the IA-PC HPET (High Precision Event Timer) to manage
385 time in preference to the PIT and RTC, if a HPET is
386 present. The HPET provides a stable time base on SMP
387 systems, unlike the TSC, but it is more expensive to access,
388 as it is off-chip. You can find the HPET spec at
389 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
391 config HPET_EMULATE_RTC
392 bool "Provide RTC interrupt"
393 depends on HPET_TIMER && RTC=y
395 # Mark as embedded because too many people got it wrong.
396 # The code disables itself when not needed.
398 bool "IOMMU support" if EMBEDDED
404 Support for full DMA access of devices with 32bit memory access only
405 on systems with more than 3GB. This is usually needed for USB,
406 sound, many IDE/SATA chipsets and some other devices.
407 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
408 based IOMMU and a software bounce buffer based IOMMU used on Intel
409 systems and as fallback.
410 The code is only active when needed (enough memory and limited
411 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
415 bool "IBM Calgary IOMMU support"
418 depends on PCI && EXPERIMENTAL
420 Support for hardware IOMMUs in IBM's xSeries x366 and x460
421 systems. Needed to run systems with more than 3GB of memory
422 properly with 32-bit PCI devices that do not support DAC
423 (Double Address Cycle). Calgary also supports bus level
424 isolation, where all DMAs pass through the IOMMU. This
425 prevents them from going anywhere except their intended
426 destination. This catches hard-to-find kernel bugs and
427 mis-behaving drivers and devices that do not use the DMA-API
428 properly to set up their DMA buffers. The IOMMU can be
429 turned off at boot time with the iommu=off parameter.
430 Normally the kernel will make the right choice by itself.
433 # need this always selected by IOMMU for the VIA workaround
438 bool "Machine check support" if EMBEDDED
441 Include a machine check error handler to report hardware errors.
442 This version will require the mcelog utility to decode some
443 machine check error logs. See
444 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
447 bool "Intel MCE features"
448 depends on X86_MCE && X86_LOCAL_APIC
451 Additional support for intel specific MCE features such as
455 bool "AMD MCE features"
456 depends on X86_MCE && X86_LOCAL_APIC
459 Additional support for AMD specific MCE features such as
460 the DRAM Error Threshold.
463 bool "kexec system call (EXPERIMENTAL)"
464 depends on EXPERIMENTAL
466 kexec is a system call that implements the ability to shutdown your
467 current kernel, and to start another kernel. It is like a reboot
468 but it is independent of the system firmware. And like a reboot
469 you can start any kernel with it, not just Linux.
471 The name comes from the similarity to the exec system call.
473 It is an ongoing process to be certain the hardware in a machine
474 is properly shutdown, so do not be surprised if this code does not
475 initially work for you. It may help to enable device hotplugging
476 support. As of this writing the exact hardware interface is
477 strongly in flux, so no good recommendation can be made.
480 bool "kernel crash dumps (EXPERIMENTAL)"
481 depends on EXPERIMENTAL
483 Generate crash dump after being started by kexec.
485 config PHYSICAL_START
486 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
487 default "0x1000000" if CRASH_DUMP
490 This gives the physical address where the kernel is loaded. Normally
491 for regular kernels this value is 0x200000 (2MB). But in the case
492 of kexec on panic the fail safe kernel needs to run at a different
493 address than the panic-ed kernel. This option is used to set the load
494 address for kernels used to capture crash dump on being kexec'ed
495 after panic. The default value for crash dump kernels is
496 0x1000000 (16MB). This can also be set based on the "X" value as
497 specified in the "crashkernel=YM@XM" command line boot parameter
498 passed to the panic-ed kernel. Typically this parameter is set as
499 crashkernel=64M@16M. Please take a look at
500 Documentation/kdump/kdump.txt for more details about crash dumps.
502 Don't change this unless you know what you are doing.
505 bool "Enable seccomp to safely compute untrusted bytecode"
509 This kernel feature is useful for number crunching applications
510 that may need to compute untrusted bytecode during their
511 execution. By using pipes or other transports made available to
512 the process as file descriptors supporting the read/write
513 syscalls, it's possible to isolate those applications in
514 their own address space using seccomp. Once seccomp is
515 enabled via /proc/<pid>/seccomp, it cannot be disabled
516 and the task is only allowed to execute a few safe syscalls
517 defined by each seccomp mode.
519 If unsure, say Y. Only embedded should say N here.
521 source kernel/Kconfig.hz
524 bool "Function reordering"
527 This option enables the toolchain to reorder functions for a more
528 optimal TLB usage. If you have pretty much any version of binutils,
529 this can increase your kernel build time by roughly one minute.
533 depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
538 # Use the generic interrupt handling code in kernel/irq/:
540 config GENERIC_HARDIRQS
544 config GENERIC_IRQ_PROBE
548 # we have no ISA slots, but we do have ISA-style DMA.
553 config GENERIC_PENDING_IRQ
555 depends on GENERIC_HARDIRQS && SMP
558 menu "Power management options"
560 source kernel/power/Kconfig
562 source "drivers/acpi/Kconfig"
564 source "arch/x86_64/kernel/cpufreq/Kconfig"
568 menu "Bus options (PCI etc.)"
573 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
580 bool "Support mmconfig PCI config space access"
581 depends on PCI && ACPI
583 source "drivers/pci/pcie/Kconfig"
585 source "drivers/pci/Kconfig"
587 source "drivers/pcmcia/Kconfig"
589 source "drivers/pci/hotplug/Kconfig"
594 menu "Executable file formats / Emulations"
596 source "fs/Kconfig.binfmt"
598 config IA32_EMULATION
599 bool "IA32 Emulation"
601 Include code to run 32-bit programs under a 64-bit kernel. You should likely
602 turn this on, unless you're 100% sure that you don't have any 32-bit programs
606 tristate "IA32 a.out support"
607 depends on IA32_EMULATION
609 Support old a.out binaries in the 32bit emulation.
613 depends on IA32_EMULATION
616 config SYSVIPC_COMPAT
618 depends on COMPAT && SYSVIPC
625 source drivers/Kconfig
627 source "drivers/firmware/Kconfig"
631 menu "Instrumentation Support"
632 depends on EXPERIMENTAL
634 source "arch/x86_64/oprofile/Kconfig"
637 bool "Kprobes (EXPERIMENTAL)"
638 depends on EXPERIMENTAL && MODULES
640 Kprobes allows you to trap at almost any kernel address and
641 execute a callback function. register_kprobe() establishes
642 a probepoint and specifies the callback. Kprobes is useful
643 for kernel debugging, non-intrusive instrumentation and testing.
644 If in doubt, say "N".
647 source "arch/x86_64/Kconfig.debug"
649 source "security/Kconfig"
651 source "crypto/Kconfig"