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
286 int "Maximum number of CPUs (2-256)"
291 This allows you to specify the maximum number of CPUs which this
292 kernel will support. Current maximum is 256 CPUs due to
293 APIC addressing limits. Less depending on the hardware.
295 This is purely to save memory - each supported CPU requires
296 memory in the static kernel configuration.
299 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
300 depends on SMP && HOTPLUG && EXPERIMENTAL
302 Say Y here to experiment with turning CPUs off and on. CPUs
303 can be controlled through /sys/devices/system/cpu/cpu#.
304 Say N if you want to disable CPU hotplug.
311 Use the IA-PC HPET (High Precision Event Timer) to manage
312 time in preference to the PIT and RTC, if a HPET is
313 present. The HPET provides a stable time base on SMP
314 systems, unlike the TSC, but it is more expensive to access,
315 as it is off-chip. You can find the HPET spec at
316 <http://www.intel.com/labs/platcomp/hpet/hpetspec.htm>.
323 Support the ACPI PM timer for time keeping. This is slow,
324 but is useful on some chipsets without HPET on systems with more
325 than one CPU. On a single processor or single socket multi core
326 system it is normally not required.
327 When the PM timer is active 64bit vsyscalls are disabled
328 and should not be enabled (/proc/sys/kernel/vsyscall64 should
330 The kernel selects the PM timer only as a last resort, so it is
331 useful to enable just in case.
333 config HPET_EMULATE_RTC
334 bool "Provide RTC interrupt"
335 depends on HPET_TIMER && RTC=y
342 Support the IOMMU. Needed to run systems with more than 3GB of memory
343 properly with 32-bit PCI devices that do not support DAC (Double Address
344 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
345 Normally the kernel will take the right choice by itself.
346 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
347 and a software emulation used on some other systems.
350 # need this always enabled with GART_IOMMU for the VIA workaround
353 depends on GART_IOMMU
358 depends on !GART_IOMMU && !SWIOTLB
361 Don't use IOMMU code. This will cause problems when you have more than 4GB
362 of memory and any 32-bit devices. Don't turn on unless you know what you
366 bool "Machine check support" if EMBEDDED
369 Include a machine check error handler to report hardware errors.
370 This version will require the mcelog utility to decode some
371 machine check error logs. See
372 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
375 bool "Intel MCE features"
376 depends on X86_MCE && X86_LOCAL_APIC
379 Additional support for intel specific MCE features such as
382 config PHYSICAL_START
383 hex "Physical address where the kernel is loaded" if EMBEDDED
386 This gives the physical address where the kernel is loaded.
387 Primarily used in the case of kexec on panic where the
388 fail safe kernel needs to run at a different address than
391 Don't change this unless you know what you are doing.
394 bool "kexec system call (EXPERIMENTAL)"
395 depends on EXPERIMENTAL
397 kexec is a system call that implements the ability to shutdown your
398 current kernel, and to start another kernel. It is like a reboot
399 but it is indepedent of the system firmware. And like a reboot
400 you can start any kernel with it, not just Linux.
402 The name comes from the similiarity to the exec system call.
404 It is an ongoing process to be certain the hardware in a machine
405 is properly shutdown, so do not be surprised if this code does not
406 initially work for you. It may help to enable device hotplugging
407 support. As of this writing the exact hardware interface is
408 strongly in flux, so no good recommendation can be made.
411 bool "Enable seccomp to safely compute untrusted bytecode"
415 This kernel feature is useful for number crunching applications
416 that may need to compute untrusted bytecode during their
417 execution. By using pipes or other transports made available to
418 the process as file descriptors supporting the read/write
419 syscalls, it's possible to isolate those applications in
420 their own address space using seccomp. Once seccomp is
421 enabled via /proc/<pid>/seccomp, it cannot be disabled
422 and the task is only allowed to execute a few safe syscalls
423 defined by each seccomp mode.
425 If unsure, say Y. Only embedded should say N here.
427 source kernel/Kconfig.hz
432 # Use the generic interrupt handling code in kernel/irq/:
434 config GENERIC_HARDIRQS
438 config GENERIC_IRQ_PROBE
442 # we have no ISA slots, but we do have ISA-style DMA.
447 config GENERIC_PENDING_IRQ
449 depends on GENERIC_HARDIRQS && SMP
452 menu "Power management options"
454 source kernel/power/Kconfig
456 source "drivers/acpi/Kconfig"
458 source "arch/x86_64/kernel/cpufreq/Kconfig"
462 menu "Bus options (PCI etc.)"
467 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
474 bool "Support mmconfig PCI config space access"
475 depends on PCI && ACPI
478 bool "Unordered IO mapping access"
479 depends on EXPERIMENTAL
481 Use unordered stores to access IO memory mappings in device drivers.
482 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
483 work with this option, but it makes the drivers behave differently
484 from i386. Requires that the driver writer used memory barriers
487 source "drivers/pci/pcie/Kconfig"
489 source "drivers/pci/Kconfig"
491 source "drivers/pcmcia/Kconfig"
493 source "drivers/pci/hotplug/Kconfig"
498 menu "Executable file formats / Emulations"
500 source "fs/Kconfig.binfmt"
502 config IA32_EMULATION
503 bool "IA32 Emulation"
505 Include code to run 32-bit programs under a 64-bit kernel. You should likely
506 turn this on, unless you're 100% sure that you don't have any 32-bit programs
510 bool "IA32 a.out support"
511 depends on IA32_EMULATION
513 Support old a.out binaries in the 32bit emulation.
517 depends on IA32_EMULATION
520 config SYSVIPC_COMPAT
522 depends on COMPAT && SYSVIPC
527 depends on IA32_EMULATION
534 source drivers/Kconfig
536 source "drivers/firmware/Kconfig"
540 source "arch/x86_64/oprofile/Kconfig"
542 source "arch/x86_64/Kconfig.debug"
544 source "security/Kconfig"
546 source "crypto/Kconfig"