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 SEMAPHORE_SLEEPERS
41 config RWSEM_GENERIC_SPINLOCK
45 config RWSEM_XCHGADD_ALGORITHM
48 config GENERIC_HWEIGHT
52 config GENERIC_CALIBRATE_DELAY
64 config GENERIC_ISA_DMA
72 config ARCH_MAY_HAVE_PC_FDC
83 menu "Processor type and features"
86 prompt "Subarchitecture Type"
92 Choose this option if your computer is a standard PC or compatible.
95 bool "Support for ScaleMP vSMP"
97 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
98 supposed to run on these EM64T-based machines. Only choose this option
99 if you have one of these machines.
104 prompt "Processor family"
108 bool "AMD-Opteron/Athlon64"
110 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
115 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
116 Extended Memory 64 Technology(EM64T). For details see
117 <http://www.intel.com/technology/64bitextensions/>.
120 bool "Generic-x86-64"
127 # Define implied options from the CPU selection here
129 config X86_L1_CACHE_BYTES
131 default "128" if GENERIC_CPU || MPSC
134 config X86_L1_CACHE_SHIFT
136 default "7" if GENERIC_CPU || MPSC
139 config X86_INTERNODE_CACHE_BYTES
141 default "4096" if X86_VSMP
142 default X86_L1_CACHE_BYTES if !X86_VSMP
153 tristate "/dev/cpu/microcode - Intel CPU microcode support"
155 If you say Y here the 'File systems' section, you will be
156 able to update the microcode on Intel processors. You will
157 obviously need the actual microcode binary data itself which is
158 not shipped with the Linux kernel.
160 For latest news and information on obtaining all the required
161 ingredients for this driver, check:
162 <http://www.urbanmyth.org/microcode/>.
164 To compile this driver as a module, choose M here: the
165 module will be called microcode.
166 If you use modprobe or kmod you may also want to add the line
167 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
170 tristate "/dev/cpu/*/msr - Model-specific register support"
172 This device gives privileged processes access to the x86
173 Model-Specific Registers (MSRs). It is a character device with
174 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
175 MSR accesses are directed to a specific CPU on multi-processor
179 tristate "/dev/cpu/*/cpuid - CPU information support"
181 This device gives processes access to the x86 CPUID instruction to
182 be executed on a specific processor. It is a character device
183 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
188 depends on SMP && !MK8
191 config MATH_EMULATION
204 config X86_LOCAL_APIC
209 bool "MTRR (Memory Type Range Register) support"
211 On Intel P6 family processors (Pentium Pro, Pentium II and later)
212 the Memory Type Range Registers (MTRRs) may be used to control
213 processor access to memory ranges. This is most useful if you have
214 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
215 allows bus write transfers to be combined into a larger transfer
216 before bursting over the PCI/AGP bus. This can increase performance
217 of image write operations 2.5 times or more. Saying Y here creates a
218 /proc/mtrr file which may be used to manipulate your processor's
219 MTRRs. Typically the X server should use this.
221 This code has a reasonably generic interface so that similar
222 control registers on other processors can be easily supported
225 Saying Y here also fixes a problem with buggy SMP BIOSes which only
226 set the MTRRs for the boot CPU and not for the secondary CPUs. This
227 can lead to all sorts of problems, so it's good to say Y here.
229 Just say Y here, all x86-64 machines support MTRRs.
231 See <file:Documentation/mtrr.txt> for more information.
234 bool "Symmetric multi-processing support"
236 This enables support for systems with more than one CPU. If you have
237 a system with only one CPU, like most personal computers, say N. If
238 you have a system with more than one CPU, say Y.
240 If you say N here, the kernel will run on single and multiprocessor
241 machines, but will use only one CPU of a multiprocessor machine. If
242 you say Y here, the kernel will run on many, but not all,
243 singleprocessor machines. On a singleprocessor machine, the kernel
244 will run faster if you say N here.
246 If you don't know what to do here, say N.
249 bool "SMT (Hyperthreading) scheduler support"
253 SMT scheduler support improves the CPU scheduler's decision making
254 when dealing with Intel Pentium 4 chips with HyperThreading at a
255 cost of slightly increased overhead in some places. If unsure say
259 bool "Multi-core scheduler support"
263 Multi-core scheduler support improves the CPU scheduler's decision
264 making when dealing with multi-core CPU chips at a cost of slightly
265 increased overhead in some places. If unsure say N here.
267 source "kernel/Kconfig.preempt"
270 bool "Non Uniform Memory Access (NUMA) Support"
273 Enable NUMA (Non Uniform Memory Access) support. The kernel
274 will try to allocate memory used by a CPU on the local memory
275 controller of the CPU and add some more NUMA awareness to the kernel.
276 This code is recommended on all multiprocessor Opteron systems.
277 If the system is EM64T, you should say N unless your system is EM64T
281 bool "Old style AMD Opteron NUMA detection"
285 Enable K8 NUMA node topology detection. You should say Y here if
286 you have a multi processor AMD K8 system. This uses an old
287 method to read the NUMA configurtion directly from the builtin
288 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
289 instead, which also takes priority if both are compiled in.
294 depends on NEED_MULTIPLE_NODES
296 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
298 config X86_64_ACPI_NUMA
299 bool "ACPI NUMA detection"
306 Enable ACPI SRAT based node topology detection.
309 bool "NUMA emulation"
312 Enable NUMA emulation. A flat machine will be split
313 into virtual nodes when booted with "numa=fake=N", where N is the
314 number of nodes. This is only useful for debugging.
316 config ARCH_DISCONTIGMEM_ENABLE
322 config ARCH_DISCONTIGMEM_ENABLE
326 config ARCH_DISCONTIGMEM_DEFAULT
330 config ARCH_SPARSEMEM_ENABLE
332 depends on (NUMA || EXPERIMENTAL)
334 config ARCH_MEMORY_PROBE
336 depends on MEMORY_HOTPLUG
338 config ARCH_FLATMEM_ENABLE
344 config HAVE_ARCH_EARLY_PFN_TO_NID
348 config OUT_OF_LINE_PFN_TO_PAGE
350 depends on DISCONTIGMEM
353 int "Maximum number of CPUs (2-256)"
358 This allows you to specify the maximum number of CPUs which this
359 kernel will support. Current maximum is 256 CPUs due to
360 APIC addressing limits. Less depending on the hardware.
362 This is purely to save memory - each supported CPU requires
363 memory in the static kernel configuration.
366 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
367 depends on SMP && HOTPLUG && EXPERIMENTAL
369 Say Y here to experiment with turning CPUs off and on. CPUs
370 can be controlled through /sys/devices/system/cpu/cpu#.
371 Say N if you want to disable CPU hotplug.
378 Use the IA-PC HPET (High Precision Event Timer) to manage
379 time in preference to the PIT and RTC, if a HPET is
380 present. The HPET provides a stable time base on SMP
381 systems, unlike the TSC, but it is more expensive to access,
382 as it is off-chip. You can find the HPET spec at
383 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
385 config HPET_EMULATE_RTC
386 bool "Provide RTC interrupt"
387 depends on HPET_TIMER && RTC=y
389 # Mark as embedded because too many people got it wrong.
390 # The code disables itself when not needed.
392 bool "IOMMU support" if EMBEDDED
398 Support for full DMA access of devices with 32bit memory access only
399 on systems with more than 3GB. This is usually needed for USB,
400 sound, many IDE/SATA chipsets and some other devices.
401 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
402 based IOMMU and a software bounce buffer based IOMMU used on Intel
403 systems and as fallback.
404 The code is only active when needed (enough memory and limited
405 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
408 # need this always selected by IOMMU for the VIA workaround
413 bool "Machine check support" if EMBEDDED
416 Include a machine check error handler to report hardware errors.
417 This version will require the mcelog utility to decode some
418 machine check error logs. See
419 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
422 bool "Intel MCE features"
423 depends on X86_MCE && X86_LOCAL_APIC
426 Additional support for intel specific MCE features such as
430 bool "AMD MCE features"
431 depends on X86_MCE && X86_LOCAL_APIC
434 Additional support for AMD specific MCE features such as
435 the DRAM Error Threshold.
438 bool "kexec system call (EXPERIMENTAL)"
439 depends on EXPERIMENTAL
441 kexec is a system call that implements the ability to shutdown your
442 current kernel, and to start another kernel. It is like a reboot
443 but it is indepedent of the system firmware. And like a reboot
444 you can start any kernel with it, not just Linux.
446 The name comes from the similiarity to the exec system call.
448 It is an ongoing process to be certain the hardware in a machine
449 is properly shutdown, so do not be surprised if this code does not
450 initially work for you. It may help to enable device hotplugging
451 support. As of this writing the exact hardware interface is
452 strongly in flux, so no good recommendation can be made.
455 bool "kernel crash dumps (EXPERIMENTAL)"
456 depends on EXPERIMENTAL
458 Generate crash dump after being started by kexec.
460 config PHYSICAL_START
461 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
462 default "0x1000000" if CRASH_DUMP
465 This gives the physical address where the kernel is loaded. Normally
466 for regular kernels this value is 0x200000 (2MB). But in the case
467 of kexec on panic the fail safe kernel needs to run at a different
468 address than the panic-ed kernel. This option is used to set the load
469 address for kernels used to capture crash dump on being kexec'ed
470 after panic. The default value for crash dump kernels is
471 0x1000000 (16MB). This can also be set based on the "X" value as
472 specified in the "crashkernel=YM@XM" command line boot parameter
473 passed to the panic-ed kernel. Typically this parameter is set as
474 crashkernel=64M@16M. Please take a look at
475 Documentation/kdump/kdump.txt for more details about crash dumps.
477 Don't change this unless you know what you are doing.
480 bool "Enable seccomp to safely compute untrusted bytecode"
484 This kernel feature is useful for number crunching applications
485 that may need to compute untrusted bytecode during their
486 execution. By using pipes or other transports made available to
487 the process as file descriptors supporting the read/write
488 syscalls, it's possible to isolate those applications in
489 their own address space using seccomp. Once seccomp is
490 enabled via /proc/<pid>/seccomp, it cannot be disabled
491 and the task is only allowed to execute a few safe syscalls
492 defined by each seccomp mode.
494 If unsure, say Y. Only embedded should say N here.
496 source kernel/Kconfig.hz
499 bool "Function reordering"
502 This option enables the toolchain to reorder functions for a more
503 optimal TLB usage. If you have pretty much any version of binutils,
504 this can increase your kernel build time by roughly one minute.
508 depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
513 # Use the generic interrupt handling code in kernel/irq/:
515 config GENERIC_HARDIRQS
519 config GENERIC_IRQ_PROBE
523 # we have no ISA slots, but we do have ISA-style DMA.
528 config GENERIC_PENDING_IRQ
530 depends on GENERIC_HARDIRQS && SMP
533 menu "Power management options"
535 source kernel/power/Kconfig
537 source "drivers/acpi/Kconfig"
539 source "arch/x86_64/kernel/cpufreq/Kconfig"
543 menu "Bus options (PCI etc.)"
548 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
555 bool "Support mmconfig PCI config space access"
556 depends on PCI && ACPI
558 source "drivers/pci/pcie/Kconfig"
560 source "drivers/pci/Kconfig"
562 source "drivers/pcmcia/Kconfig"
564 source "drivers/pci/hotplug/Kconfig"
569 menu "Executable file formats / Emulations"
571 source "fs/Kconfig.binfmt"
573 config IA32_EMULATION
574 bool "IA32 Emulation"
576 Include code to run 32-bit programs under a 64-bit kernel. You should likely
577 turn this on, unless you're 100% sure that you don't have any 32-bit programs
581 tristate "IA32 a.out support"
582 depends on IA32_EMULATION
584 Support old a.out binaries in the 32bit emulation.
588 depends on IA32_EMULATION
591 config SYSVIPC_COMPAT
593 depends on COMPAT && SYSVIPC
600 source drivers/Kconfig
602 source "drivers/firmware/Kconfig"
606 menu "Instrumentation Support"
607 depends on EXPERIMENTAL
609 source "arch/x86_64/oprofile/Kconfig"
612 bool "Kprobes (EXPERIMENTAL)"
613 depends on EXPERIMENTAL && MODULES
615 Kprobes allows you to trap at almost any kernel address and
616 execute a callback function. register_kprobe() establishes
617 a probepoint and specifies the callback. Kprobes is useful
618 for kernel debugging, non-intrusive instrumentation and testing.
619 If in doubt, say "N".
622 source "arch/x86_64/Kconfig.debug"
624 source "security/Kconfig"
626 source "crypto/Kconfig"