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/>.
37 config RWSEM_GENERIC_SPINLOCK
41 config RWSEM_XCHGADD_ALGORITHM
44 config GENERIC_CALIBRATE_DELAY
56 config GENERIC_ISA_DMA
67 menu "Processor type and features"
70 prompt "Processor family"
74 bool "AMD-Opteron/Athlon64"
76 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
81 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
82 Extended Memory 64 Technology(EM64T). For details see
83 <http://www.intel.com/technology/64bitextensions/>.
93 # Define implied options from the CPU selection here
95 config X86_L1_CACHE_BYTES
97 default "128" if GENERIC_CPU || MPSC
100 config X86_L1_CACHE_SHIFT
102 default "7" if GENERIC_CPU || MPSC
114 tristate "/dev/cpu/microcode - Intel CPU microcode support"
116 If you say Y here the 'File systems' section, you will be
117 able to update the microcode on Intel processors. You will
118 obviously need the actual microcode binary data itself which is
119 not shipped with the Linux kernel.
121 For latest news and information on obtaining all the required
122 ingredients for this driver, check:
123 <http://www.urbanmyth.org/microcode/>.
125 To compile this driver as a module, choose M here: the
126 module will be called microcode.
127 If you use modprobe or kmod you may also want to add the line
128 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
131 tristate "/dev/cpu/*/msr - Model-specific register support"
133 This device gives privileged processes access to the x86
134 Model-Specific Registers (MSRs). It is a character device with
135 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
136 MSR accesses are directed to a specific CPU on multi-processor
140 tristate "/dev/cpu/*/cpuid - CPU information support"
142 This device gives processes access to the x86 CPUID instruction to
143 be executed on a specific processor. It is a character device
144 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
149 depends on SMP && !MK8
152 config MATH_EMULATION
165 config X86_LOCAL_APIC
170 bool "MTRR (Memory Type Range Register) support"
172 On Intel P6 family processors (Pentium Pro, Pentium II and later)
173 the Memory Type Range Registers (MTRRs) may be used to control
174 processor access to memory ranges. This is most useful if you have
175 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
176 allows bus write transfers to be combined into a larger transfer
177 before bursting over the PCI/AGP bus. This can increase performance
178 of image write operations 2.5 times or more. Saying Y here creates a
179 /proc/mtrr file which may be used to manipulate your processor's
180 MTRRs. Typically the X server should use this.
182 This code has a reasonably generic interface so that similar
183 control registers on other processors can be easily supported
186 Saying Y here also fixes a problem with buggy SMP BIOSes which only
187 set the MTRRs for the boot CPU and not for the secondary CPUs. This
188 can lead to all sorts of problems, so it's good to say Y here.
190 Just say Y here, all x86-64 machines support MTRRs.
192 See <file:Documentation/mtrr.txt> for more information.
195 bool "Symmetric multi-processing support"
197 This enables support for systems with more than one CPU. If you have
198 a system with only one CPU, like most personal computers, say N. If
199 you have a system with more than one CPU, say Y.
201 If you say N here, the kernel will run on single and multiprocessor
202 machines, but will use only one CPU of a multiprocessor machine. If
203 you say Y here, the kernel will run on many, but not all,
204 singleprocessor machines. On a singleprocessor machine, the kernel
205 will run faster if you say N here.
207 If you don't know what to do here, say N.
210 bool "SMT (Hyperthreading) scheduler support"
214 SMT scheduler support improves the CPU scheduler's decision making
215 when dealing with Intel Pentium 4 chips with HyperThreading at a
216 cost of slightly increased overhead in some places. If unsure say
219 source "kernel/Kconfig.preempt"
222 bool "K8 NUMA support"
226 Enable NUMA (Non Unified Memory Architecture) support for
227 AMD Opteron Multiprocessor systems. The kernel will try to allocate
228 memory used by a CPU on the local memory controller of the CPU
229 and add some more NUMA awareness to the kernel.
230 This code is recommended on all multiprocessor Opteron systems
231 and normally doesn't hurt on others.
234 bool "NUMA emulation support"
238 Enable NUMA emulation. A flat machine will be split
239 into virtual nodes when booted with "numa=fake=N", where N is the
240 number of nodes. This is only useful for debugging.
242 config ARCH_DISCONTIGMEM_ENABLE
251 config ARCH_DISCONTIGMEM_ENABLE
255 config ARCH_DISCONTIGMEM_DEFAULT
259 config ARCH_SPARSEMEM_ENABLE
263 config ARCH_FLATMEM_ENABLE
269 config HAVE_ARCH_EARLY_PFN_TO_NID
278 int "Maximum number of CPUs (2-256)"
283 This allows you to specify the maximum number of CPUs which this
284 kernel will support. Current maximum is 256 CPUs due to
285 APIC addressing limits. Less depending on the hardware.
287 This is purely to save memory - each supported CPU requires
288 memory in the static kernel configuration.
291 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
292 depends on SMP && HOTPLUG && EXPERIMENTAL
294 Say Y here to experiment with turning CPUs off and on. CPUs
295 can be controlled through /sys/devices/system/cpu/cpu#.
296 Say N if you want to disable CPU hotplug.
303 Use the IA-PC HPET (High Precision Event Timer) to manage
304 time in preference to the PIT and RTC, if a HPET is
305 present. The HPET provides a stable time base on SMP
306 systems, unlike the TSC, but it is more expensive to access,
307 as it is off-chip. You can find the HPET spec at
308 <http://www.intel.com/labs/platcomp/hpet/hpetspec.htm>.
315 Support the ACPI PM timer for time keeping. This is slow,
316 but is useful on some chipsets without HPET on systems with more
317 than one CPU. On a single processor or single socket multi core
318 system it is normally not required.
319 When the PM timer is active 64bit vsyscalls are disabled
320 and should not be enabled (/proc/sys/kernel/vsyscall64 should
322 The kernel selects the PM timer only as a last resort, so it is
323 useful to enable just in case.
325 config HPET_EMULATE_RTC
326 bool "Provide RTC interrupt"
327 depends on HPET_TIMER && RTC=y
334 Support the IOMMU. Needed to run systems with more than 3GB of memory
335 properly with 32-bit PCI devices that do not support DAC (Double Address
336 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
337 Normally the kernel will take the right choice by itself.
338 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
339 and a software emulation used on some other systems.
342 # need this always enabled with GART_IOMMU for the VIA workaround
345 depends on GART_IOMMU
350 depends on !GART_IOMMU && !SWIOTLB
353 Don't use IOMMU code. This will cause problems when you have more than 4GB
354 of memory and any 32-bit devices. Don't turn on unless you know what you
358 bool "Machine check support" if EMBEDDED
361 Include a machine check error handler to report hardware errors.
362 This version will require the mcelog utility to decode some
363 machine check error logs. See
364 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
367 bool "Intel MCE features"
368 depends on X86_MCE && X86_LOCAL_APIC
371 Additional support for intel specific MCE features such as
374 config PHYSICAL_START
375 hex "Physical address where the kernel is loaded" if EMBEDDED
378 This gives the physical address where the kernel is loaded.
379 Primarily used in the case of kexec on panic where the
380 fail safe kernel needs to run at a different address than
383 Don't change this unless you know what you are doing.
386 bool "kexec system call (EXPERIMENTAL)"
387 depends on EXPERIMENTAL
389 kexec is a system call that implements the ability to shutdown your
390 current kernel, and to start another kernel. It is like a reboot
391 but it is indepedent of the system firmware. And like a reboot
392 you can start any kernel with it, not just Linux.
394 The name comes from the similiarity to the exec system call.
396 It is an ongoing process to be certain the hardware in a machine
397 is properly shutdown, so do not be surprised if this code does not
398 initially work for you. It may help to enable device hotplugging
399 support. As of this writing the exact hardware interface is
400 strongly in flux, so no good recommendation can be made.
403 bool "Enable seccomp to safely compute untrusted bytecode"
407 This kernel feature is useful for number crunching applications
408 that may need to compute untrusted bytecode during their
409 execution. By using pipes or other transports made available to
410 the process as file descriptors supporting the read/write
411 syscalls, it's possible to isolate those applications in
412 their own address space using seccomp. Once seccomp is
413 enabled via /proc/<pid>/seccomp, it cannot be disabled
414 and the task is only allowed to execute a few safe syscalls
415 defined by each seccomp mode.
417 If unsure, say Y. Only embedded should say N here.
419 source kernel/Kconfig.hz
424 # Use the generic interrupt handling code in kernel/irq/:
426 config GENERIC_HARDIRQS
430 config GENERIC_IRQ_PROBE
434 # we have no ISA slots, but we do have ISA-style DMA.
439 menu "Power management options"
441 source kernel/power/Kconfig
443 source "drivers/acpi/Kconfig"
445 source "arch/x86_64/kernel/cpufreq/Kconfig"
449 menu "Bus options (PCI etc.)"
454 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
461 bool "Support mmconfig PCI config space access"
462 depends on PCI && ACPI
465 bool "Unordered IO mapping access"
466 depends on EXPERIMENTAL
468 Use unordered stores to access IO memory mappings in device drivers.
469 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
470 work with this option, but it makes the drivers behave differently
471 from i386. Requires that the driver writer used memory barriers
474 source "drivers/pci/pcie/Kconfig"
476 source "drivers/pci/Kconfig"
478 source "drivers/pcmcia/Kconfig"
480 source "drivers/pci/hotplug/Kconfig"
485 menu "Executable file formats / Emulations"
487 source "fs/Kconfig.binfmt"
489 config IA32_EMULATION
490 bool "IA32 Emulation"
492 Include code to run 32-bit programs under a 64-bit kernel. You should likely
493 turn this on, unless you're 100% sure that you don't have any 32-bit programs
497 bool "IA32 a.out support"
498 depends on IA32_EMULATION
500 Support old a.out binaries in the 32bit emulation.
504 depends on IA32_EMULATION
507 config SYSVIPC_COMPAT
509 depends on COMPAT && SYSVIPC
514 depends on IA32_EMULATION
521 source drivers/Kconfig
523 source "drivers/firmware/Kconfig"
527 source "arch/x86_64/oprofile/Kconfig"
529 source "arch/x86_64/Kconfig.debug"
531 source "security/Kconfig"
533 source "crypto/Kconfig"