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_CALIBRATE_DELAY
60 config GENERIC_ISA_DMA
68 config ARCH_MAY_HAVE_PC_FDC
79 menu "Processor type and features"
82 prompt "Subarchitecture Type"
88 Choose this option if your computer is a standard PC or compatible.
91 bool "Support for ScaleMP vSMP"
93 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
94 supposed to run on these EM64T-based machines. Only choose this option
95 if you have one of these machines.
100 prompt "Processor family"
104 bool "AMD-Opteron/Athlon64"
106 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
111 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
112 Extended Memory 64 Technology(EM64T). For details see
113 <http://www.intel.com/technology/64bitextensions/>.
116 bool "Generic-x86-64"
123 # Define implied options from the CPU selection here
125 config X86_L1_CACHE_BYTES
127 default "128" if GENERIC_CPU || MPSC
130 config X86_L1_CACHE_SHIFT
132 default "7" if GENERIC_CPU || MPSC
144 tristate "/dev/cpu/microcode - Intel CPU microcode support"
146 If you say Y here the 'File systems' section, you will be
147 able to update the microcode on Intel processors. You will
148 obviously need the actual microcode binary data itself which is
149 not shipped with the Linux kernel.
151 For latest news and information on obtaining all the required
152 ingredients for this driver, check:
153 <http://www.urbanmyth.org/microcode/>.
155 To compile this driver as a module, choose M here: the
156 module will be called microcode.
157 If you use modprobe or kmod you may also want to add the line
158 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
161 tristate "/dev/cpu/*/msr - Model-specific register support"
163 This device gives privileged processes access to the x86
164 Model-Specific Registers (MSRs). It is a character device with
165 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
166 MSR accesses are directed to a specific CPU on multi-processor
170 tristate "/dev/cpu/*/cpuid - CPU information support"
172 This device gives processes access to the x86 CPUID instruction to
173 be executed on a specific processor. It is a character device
174 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
179 depends on SMP && !MK8
182 config MATH_EMULATION
195 config X86_LOCAL_APIC
200 bool "MTRR (Memory Type Range Register) support"
202 On Intel P6 family processors (Pentium Pro, Pentium II and later)
203 the Memory Type Range Registers (MTRRs) may be used to control
204 processor access to memory ranges. This is most useful if you have
205 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
206 allows bus write transfers to be combined into a larger transfer
207 before bursting over the PCI/AGP bus. This can increase performance
208 of image write operations 2.5 times or more. Saying Y here creates a
209 /proc/mtrr file which may be used to manipulate your processor's
210 MTRRs. Typically the X server should use this.
212 This code has a reasonably generic interface so that similar
213 control registers on other processors can be easily supported
216 Saying Y here also fixes a problem with buggy SMP BIOSes which only
217 set the MTRRs for the boot CPU and not for the secondary CPUs. This
218 can lead to all sorts of problems, so it's good to say Y here.
220 Just say Y here, all x86-64 machines support MTRRs.
222 See <file:Documentation/mtrr.txt> for more information.
225 bool "Symmetric multi-processing support"
227 This enables support for systems with more than one CPU. If you have
228 a system with only one CPU, like most personal computers, say N. If
229 you have a system with more than one CPU, say Y.
231 If you say N here, the kernel will run on single and multiprocessor
232 machines, but will use only one CPU of a multiprocessor machine. If
233 you say Y here, the kernel will run on many, but not all,
234 singleprocessor machines. On a singleprocessor machine, the kernel
235 will run faster if you say N here.
237 If you don't know what to do here, say N.
240 bool "SMT (Hyperthreading) scheduler support"
244 SMT scheduler support improves the CPU scheduler's decision making
245 when dealing with Intel Pentium 4 chips with HyperThreading at a
246 cost of slightly increased overhead in some places. If unsure say
249 source "kernel/Kconfig.preempt"
252 bool "Non Uniform Memory Access (NUMA) Support"
255 Enable NUMA (Non Uniform Memory Access) support. The kernel
256 will try to allocate memory used by a CPU on the local memory
257 controller of the CPU and add some more NUMA awareness to the kernel.
258 This code is recommended on all multiprocessor Opteron systems.
259 If the system is EM64T, you should say N unless your system is EM64T
263 bool "Old style AMD Opteron NUMA detection"
267 Enable K8 NUMA node topology detection. You should say Y here if
268 you have a multi processor AMD K8 system. This uses an old
269 method to read the NUMA configurtion directly from the builtin
270 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
271 instead, which also takes priority if both are compiled in.
273 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
275 config X86_64_ACPI_NUMA
276 bool "ACPI NUMA detection"
282 Enable ACPI SRAT based node topology detection.
285 bool "NUMA emulation"
288 Enable NUMA emulation. A flat machine will be split
289 into virtual nodes when booted with "numa=fake=N", where N is the
290 number of nodes. This is only useful for debugging.
292 config ARCH_DISCONTIGMEM_ENABLE
298 config ARCH_DISCONTIGMEM_ENABLE
302 config ARCH_DISCONTIGMEM_DEFAULT
306 config ARCH_SPARSEMEM_ENABLE
308 depends on (NUMA || EXPERIMENTAL)
310 config ARCH_MEMORY_PROBE
312 depends on MEMORY_HOTPLUG
314 config ARCH_FLATMEM_ENABLE
320 config HAVE_ARCH_EARLY_PFN_TO_NID
325 int "Maximum number of CPUs (2-256)"
330 This allows you to specify the maximum number of CPUs which this
331 kernel will support. Current maximum is 256 CPUs due to
332 APIC addressing limits. Less depending on the hardware.
334 This is purely to save memory - each supported CPU requires
335 memory in the static kernel configuration.
338 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
339 depends on SMP && HOTPLUG && EXPERIMENTAL
341 Say Y here to experiment with turning CPUs off and on. CPUs
342 can be controlled through /sys/devices/system/cpu/cpu#.
343 Say N if you want to disable CPU hotplug.
350 Use the IA-PC HPET (High Precision Event Timer) to manage
351 time in preference to the PIT and RTC, if a HPET is
352 present. The HPET provides a stable time base on SMP
353 systems, unlike the TSC, but it is more expensive to access,
354 as it is off-chip. You can find the HPET spec at
355 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
357 config HPET_EMULATE_RTC
358 bool "Provide RTC interrupt"
359 depends on HPET_TIMER && RTC=y
362 bool "K8 GART IOMMU support"
367 Support the IOMMU. Needed to run systems with more than 3GB of memory
368 properly with 32-bit PCI devices that do not support DAC (Double Address
369 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
370 Normally the kernel will take the right choice by itself.
371 This option includes a driver for the AMD Opteron/Athlon64 northbridge IOMMU
372 and a software emulation used on other systems.
375 # need this always enabled with GART_IOMMU for the VIA workaround
379 depends on GART_IOMMU
382 bool "Machine check support" if EMBEDDED
385 Include a machine check error handler to report hardware errors.
386 This version will require the mcelog utility to decode some
387 machine check error logs. See
388 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
391 bool "Intel MCE features"
392 depends on X86_MCE && X86_LOCAL_APIC
395 Additional support for intel specific MCE features such as
399 bool "AMD MCE features"
400 depends on X86_MCE && X86_LOCAL_APIC
403 Additional support for AMD specific MCE features such as
404 the DRAM Error Threshold.
407 bool "kexec system call (EXPERIMENTAL)"
408 depends on EXPERIMENTAL
410 kexec is a system call that implements the ability to shutdown your
411 current kernel, and to start another kernel. It is like a reboot
412 but it is indepedent of the system firmware. And like a reboot
413 you can start any kernel with it, not just Linux.
415 The name comes from the similiarity to the exec system call.
417 It is an ongoing process to be certain the hardware in a machine
418 is properly shutdown, so do not be surprised if this code does not
419 initially work for you. It may help to enable device hotplugging
420 support. As of this writing the exact hardware interface is
421 strongly in flux, so no good recommendation can be made.
424 bool "kernel crash dumps (EXPERIMENTAL)"
425 depends on EXPERIMENTAL
427 Generate crash dump after being started by kexec.
429 config PHYSICAL_START
430 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
431 default "0x1000000" if CRASH_DUMP
434 This gives the physical address where the kernel is loaded. Normally
435 for regular kernels this value is 0x200000 (2MB). But in the case
436 of kexec on panic the fail safe kernel needs to run at a different
437 address than the panic-ed kernel. This option is used to set the load
438 address for kernels used to capture crash dump on being kexec'ed
439 after panic. The default value for crash dump kernels is
440 0x1000000 (16MB). This can also be set based on the "X" value as
441 specified in the "crashkernel=YM@XM" command line boot parameter
442 passed to the panic-ed kernel. Typically this parameter is set as
443 crashkernel=64M@16M. Please take a look at
444 Documentation/kdump/kdump.txt for more details about crash dumps.
446 Don't change this unless you know what you are doing.
449 bool "Enable seccomp to safely compute untrusted bytecode"
453 This kernel feature is useful for number crunching applications
454 that may need to compute untrusted bytecode during their
455 execution. By using pipes or other transports made available to
456 the process as file descriptors supporting the read/write
457 syscalls, it's possible to isolate those applications in
458 their own address space using seccomp. Once seccomp is
459 enabled via /proc/<pid>/seccomp, it cannot be disabled
460 and the task is only allowed to execute a few safe syscalls
461 defined by each seccomp mode.
463 If unsure, say Y. Only embedded should say N here.
465 source kernel/Kconfig.hz
468 bool "Function reordering"
471 This option enables the toolchain to reorder functions for a more
472 optimal TLB usage. If you have pretty much any version of binutils,
473 this can increase your kernel build time by roughly one minute.
478 # Use the generic interrupt handling code in kernel/irq/:
480 config GENERIC_HARDIRQS
484 config GENERIC_IRQ_PROBE
488 # we have no ISA slots, but we do have ISA-style DMA.
493 config GENERIC_PENDING_IRQ
495 depends on GENERIC_HARDIRQS && SMP
498 menu "Power management options"
500 source kernel/power/Kconfig
502 source "drivers/acpi/Kconfig"
504 source "arch/x86_64/kernel/cpufreq/Kconfig"
508 menu "Bus options (PCI etc.)"
513 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
520 bool "Support mmconfig PCI config space access"
521 depends on PCI && ACPI
523 source "drivers/pci/pcie/Kconfig"
525 source "drivers/pci/Kconfig"
527 source "drivers/pcmcia/Kconfig"
529 source "drivers/pci/hotplug/Kconfig"
534 menu "Executable file formats / Emulations"
536 source "fs/Kconfig.binfmt"
538 config IA32_EMULATION
539 bool "IA32 Emulation"
541 Include code to run 32-bit programs under a 64-bit kernel. You should likely
542 turn this on, unless you're 100% sure that you don't have any 32-bit programs
546 tristate "IA32 a.out support"
547 depends on IA32_EMULATION
549 Support old a.out binaries in the 32bit emulation.
553 depends on IA32_EMULATION
556 config SYSVIPC_COMPAT
558 depends on COMPAT && SYSVIPC
565 source drivers/Kconfig
567 source "drivers/firmware/Kconfig"
571 menu "Instrumentation Support"
572 depends on EXPERIMENTAL
574 source "arch/x86_64/oprofile/Kconfig"
577 bool "Kprobes (EXPERIMENTAL)"
578 depends on EXPERIMENTAL && MODULES
580 Kprobes allows you to trap at almost any kernel address and
581 execute a callback function. register_kprobe() establishes
582 a probepoint and specifies the callback. Kprobes is useful
583 for kernel debugging, non-intrusive instrumentation and testing.
584 If in doubt, say "N".
587 source "arch/x86_64/Kconfig.debug"
589 source "security/Kconfig"
591 source "crypto/Kconfig"