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
75 menu "Processor type and features"
78 prompt "Processor family"
82 bool "AMD-Opteron/Athlon64"
84 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
89 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
90 Extended Memory 64 Technology(EM64T). For details see
91 <http://www.intel.com/technology/64bitextensions/>.
101 # Define implied options from the CPU selection here
103 config X86_L1_CACHE_BYTES
105 default "128" if GENERIC_CPU || MPSC
108 config X86_L1_CACHE_SHIFT
110 default "7" if GENERIC_CPU || MPSC
122 tristate "/dev/cpu/microcode - Intel CPU microcode support"
124 If you say Y here the 'File systems' section, you will be
125 able to update the microcode on Intel processors. You will
126 obviously need the actual microcode binary data itself which is
127 not shipped with the Linux kernel.
129 For latest news and information on obtaining all the required
130 ingredients for this driver, check:
131 <http://www.urbanmyth.org/microcode/>.
133 To compile this driver as a module, choose M here: the
134 module will be called microcode.
135 If you use modprobe or kmod you may also want to add the line
136 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
139 tristate "/dev/cpu/*/msr - Model-specific register support"
141 This device gives privileged processes access to the x86
142 Model-Specific Registers (MSRs). It is a character device with
143 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
144 MSR accesses are directed to a specific CPU on multi-processor
148 tristate "/dev/cpu/*/cpuid - CPU information support"
150 This device gives processes access to the x86 CPUID instruction to
151 be executed on a specific processor. It is a character device
152 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
157 depends on SMP && !MK8
160 config MATH_EMULATION
173 config X86_LOCAL_APIC
178 bool "MTRR (Memory Type Range Register) support"
180 On Intel P6 family processors (Pentium Pro, Pentium II and later)
181 the Memory Type Range Registers (MTRRs) may be used to control
182 processor access to memory ranges. This is most useful if you have
183 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
184 allows bus write transfers to be combined into a larger transfer
185 before bursting over the PCI/AGP bus. This can increase performance
186 of image write operations 2.5 times or more. Saying Y here creates a
187 /proc/mtrr file which may be used to manipulate your processor's
188 MTRRs. Typically the X server should use this.
190 This code has a reasonably generic interface so that similar
191 control registers on other processors can be easily supported
194 Saying Y here also fixes a problem with buggy SMP BIOSes which only
195 set the MTRRs for the boot CPU and not for the secondary CPUs. This
196 can lead to all sorts of problems, so it's good to say Y here.
198 Just say Y here, all x86-64 machines support MTRRs.
200 See <file:Documentation/mtrr.txt> for more information.
203 bool "Symmetric multi-processing support"
205 This enables support for systems with more than one CPU. If you have
206 a system with only one CPU, like most personal computers, say N. If
207 you have a system with more than one CPU, say Y.
209 If you say N here, the kernel will run on single and multiprocessor
210 machines, but will use only one CPU of a multiprocessor machine. If
211 you say Y here, the kernel will run on many, but not all,
212 singleprocessor machines. On a singleprocessor machine, the kernel
213 will run faster if you say N here.
215 If you don't know what to do here, say N.
218 bool "SMT (Hyperthreading) scheduler support"
222 SMT scheduler support improves the CPU scheduler's decision making
223 when dealing with Intel Pentium 4 chips with HyperThreading at a
224 cost of slightly increased overhead in some places. If unsure say
227 source "kernel/Kconfig.preempt"
230 bool "K8 NUMA support"
234 Enable NUMA (Non Unified Memory Architecture) support for
235 AMD Opteron Multiprocessor systems. The kernel will try to allocate
236 memory used by a CPU on the local memory controller of the CPU
237 and add some more NUMA awareness to the kernel.
238 This code is recommended on all multiprocessor Opteron systems
239 and normally doesn't hurt on others.
242 bool "NUMA emulation support"
246 Enable NUMA emulation. A flat machine will be split
247 into virtual nodes when booted with "numa=fake=N", where N is the
248 number of nodes. This is only useful for debugging.
250 config ARCH_DISCONTIGMEM_ENABLE
259 config ARCH_DISCONTIGMEM_ENABLE
263 config ARCH_DISCONTIGMEM_DEFAULT
267 config ARCH_SPARSEMEM_ENABLE
271 config ARCH_FLATMEM_ENABLE
277 config HAVE_ARCH_EARLY_PFN_TO_NID
281 int "Maximum number of CPUs (2-256)"
286 This allows you to specify the maximum number of CPUs which this
287 kernel will support. Current maximum is 256 CPUs due to
288 APIC addressing limits. Less depending on the hardware.
290 This is purely to save memory - each supported CPU requires
291 memory in the static kernel configuration.
294 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
295 depends on SMP && HOTPLUG && EXPERIMENTAL
297 Say Y here to experiment with turning CPUs off and on. CPUs
298 can be controlled through /sys/devices/system/cpu/cpu#.
299 Say N if you want to disable CPU hotplug.
306 Use the IA-PC HPET (High Precision Event Timer) to manage
307 time in preference to the PIT and RTC, if a HPET is
308 present. The HPET provides a stable time base on SMP
309 systems, unlike the TSC, but it is more expensive to access,
310 as it is off-chip. You can find the HPET spec at
311 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
318 Support the ACPI PM timer for time keeping. This is slow,
319 but is useful on some chipsets without HPET on systems with more
320 than one CPU. On a single processor or single socket multi core
321 system it is normally not required.
322 When the PM timer is active 64bit vsyscalls are disabled
323 and should not be enabled (/proc/sys/kernel/vsyscall64 should
325 The kernel selects the PM timer only as a last resort, so it is
326 useful to enable just in case.
328 config HPET_EMULATE_RTC
329 bool "Provide RTC interrupt"
330 depends on HPET_TIMER && RTC=y
337 Support the IOMMU. Needed to run systems with more than 3GB of memory
338 properly with 32-bit PCI devices that do not support DAC (Double Address
339 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
340 Normally the kernel will take the right choice by itself.
341 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
342 and a software emulation used on some other systems.
345 # need this always enabled with GART_IOMMU for the VIA workaround
348 depends on GART_IOMMU
353 depends on !GART_IOMMU && !SWIOTLB
356 Don't use IOMMU code. This will cause problems when you have more than 4GB
357 of memory and any 32-bit devices. Don't turn on unless you know what you
361 bool "Machine check support" if EMBEDDED
364 Include a machine check error handler to report hardware errors.
365 This version will require the mcelog utility to decode some
366 machine check error logs. See
367 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
370 bool "Intel MCE features"
371 depends on X86_MCE && X86_LOCAL_APIC
374 Additional support for intel specific MCE features such as
377 config PHYSICAL_START
378 hex "Physical address where the kernel is loaded" if EMBEDDED
381 This gives the physical address where the kernel is loaded.
382 Primarily used in the case of kexec on panic where the
383 fail safe kernel needs to run at a different address than
386 Don't change this unless you know what you are doing.
389 bool "kexec system call (EXPERIMENTAL)"
390 depends on EXPERIMENTAL
392 kexec is a system call that implements the ability to shutdown your
393 current kernel, and to start another kernel. It is like a reboot
394 but it is indepedent of the system firmware. And like a reboot
395 you can start any kernel with it, not just Linux.
397 The name comes from the similiarity to the exec system call.
399 It is an ongoing process to be certain the hardware in a machine
400 is properly shutdown, so do not be surprised if this code does not
401 initially work for you. It may help to enable device hotplugging
402 support. As of this writing the exact hardware interface is
403 strongly in flux, so no good recommendation can be made.
406 bool "Enable seccomp to safely compute untrusted bytecode"
410 This kernel feature is useful for number crunching applications
411 that may need to compute untrusted bytecode during their
412 execution. By using pipes or other transports made available to
413 the process as file descriptors supporting the read/write
414 syscalls, it's possible to isolate those applications in
415 their own address space using seccomp. Once seccomp is
416 enabled via /proc/<pid>/seccomp, it cannot be disabled
417 and the task is only allowed to execute a few safe syscalls
418 defined by each seccomp mode.
420 If unsure, say Y. Only embedded should say N here.
422 source kernel/Kconfig.hz
427 # Use the generic interrupt handling code in kernel/irq/:
429 config GENERIC_HARDIRQS
433 config GENERIC_IRQ_PROBE
437 # we have no ISA slots, but we do have ISA-style DMA.
442 config GENERIC_PENDING_IRQ
444 depends on GENERIC_HARDIRQS && SMP
447 menu "Power management options"
449 source kernel/power/Kconfig
451 source "drivers/acpi/Kconfig"
453 source "arch/x86_64/kernel/cpufreq/Kconfig"
457 menu "Bus options (PCI etc.)"
462 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
469 bool "Support mmconfig PCI config space access"
470 depends on PCI && ACPI
473 bool "Unordered IO mapping access"
474 depends on EXPERIMENTAL
476 Use unordered stores to access IO memory mappings in device drivers.
477 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
478 work with this option, but it makes the drivers behave differently
479 from i386. Requires that the driver writer used memory barriers
482 source "drivers/pci/pcie/Kconfig"
484 source "drivers/pci/Kconfig"
486 source "drivers/pcmcia/Kconfig"
488 source "drivers/pci/hotplug/Kconfig"
493 menu "Executable file formats / Emulations"
495 source "fs/Kconfig.binfmt"
497 config IA32_EMULATION
498 bool "IA32 Emulation"
500 Include code to run 32-bit programs under a 64-bit kernel. You should likely
501 turn this on, unless you're 100% sure that you don't have any 32-bit programs
505 bool "IA32 a.out support"
506 depends on IA32_EMULATION
508 Support old a.out binaries in the 32bit emulation.
512 depends on IA32_EMULATION
515 config SYSVIPC_COMPAT
517 depends on COMPAT && SYSVIPC
522 depends on IA32_EMULATION
529 source drivers/Kconfig
531 source "drivers/firmware/Kconfig"
535 menu "Instrumentation Support"
536 depends on EXPERIMENTAL
538 source "arch/x86_64/oprofile/Kconfig"
541 bool "Kprobes (EXPERIMENTAL)"
543 Kprobes allows you to trap at almost any kernel address and
544 execute a callback function. register_kprobe() establishes
545 a probepoint and specifies the callback. Kprobes is useful
546 for kernel debugging, non-intrusive instrumentation and testing.
547 If in doubt, say "N".
550 source "arch/x86_64/Kconfig.debug"
552 source "security/Kconfig"
554 source "crypto/Kconfig"