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
71 menu "Processor type and features"
74 prompt "Processor family"
78 bool "AMD-Opteron/Athlon64"
80 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
85 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
86 Extended Memory 64 Technology(EM64T). For details see
87 <http://www.intel.com/technology/64bitextensions/>.
97 # Define implied options from the CPU selection here
99 config X86_L1_CACHE_BYTES
101 default "128" if GENERIC_CPU || MPSC
104 config X86_L1_CACHE_SHIFT
106 default "7" if GENERIC_CPU || MPSC
118 tristate "/dev/cpu/microcode - Intel CPU microcode support"
120 If you say Y here the 'File systems' section, you will be
121 able to update the microcode on Intel processors. You will
122 obviously need the actual microcode binary data itself which is
123 not shipped with the Linux kernel.
125 For latest news and information on obtaining all the required
126 ingredients for this driver, check:
127 <http://www.urbanmyth.org/microcode/>.
129 To compile this driver as a module, choose M here: the
130 module will be called microcode.
131 If you use modprobe or kmod you may also want to add the line
132 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
135 tristate "/dev/cpu/*/msr - Model-specific register support"
137 This device gives privileged processes access to the x86
138 Model-Specific Registers (MSRs). It is a character device with
139 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
140 MSR accesses are directed to a specific CPU on multi-processor
144 tristate "/dev/cpu/*/cpuid - CPU information support"
146 This device gives processes access to the x86 CPUID instruction to
147 be executed on a specific processor. It is a character device
148 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
151 # disable it for opteron optimized builds because it pulls in ACPI_BOOT
154 depends on SMP && !MK8
157 config MATH_EMULATION
170 config X86_LOCAL_APIC
175 bool "MTRR (Memory Type Range Register) support"
177 On Intel P6 family processors (Pentium Pro, Pentium II and later)
178 the Memory Type Range Registers (MTRRs) may be used to control
179 processor access to memory ranges. This is most useful if you have
180 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
181 allows bus write transfers to be combined into a larger transfer
182 before bursting over the PCI/AGP bus. This can increase performance
183 of image write operations 2.5 times or more. Saying Y here creates a
184 /proc/mtrr file which may be used to manipulate your processor's
185 MTRRs. Typically the X server should use this.
187 This code has a reasonably generic interface so that similar
188 control registers on other processors can be easily supported
191 Saying Y here also fixes a problem with buggy SMP BIOSes which only
192 set the MTRRs for the boot CPU and not for the secondary CPUs. This
193 can lead to all sorts of problems, so it's good to say Y here.
195 Just say Y here, all x86-64 machines support MTRRs.
197 See <file:Documentation/mtrr.txt> for more information.
200 bool "Symmetric multi-processing support"
202 This enables support for systems with more than one CPU. If you have
203 a system with only one CPU, like most personal computers, say N. If
204 you have a system with more than one CPU, say Y.
206 If you say N here, the kernel will run on single and multiprocessor
207 machines, but will use only one CPU of a multiprocessor machine. If
208 you say Y here, the kernel will run on many, but not all,
209 singleprocessor machines. On a singleprocessor machine, the kernel
210 will run faster if you say N here.
212 If you don't know what to do here, say N.
215 bool "SMT (Hyperthreading) scheduler support"
219 SMT scheduler support improves the CPU scheduler's decision making
220 when dealing with Intel Pentium 4 chips with HyperThreading at a
221 cost of slightly increased overhead in some places. If unsure say
224 source "kernel/Kconfig.preempt"
227 bool "K8 NUMA support"
231 Enable NUMA (Non Unified Memory Architecture) support for
232 AMD Opteron Multiprocessor systems. The kernel will try to allocate
233 memory used by a CPU on the local memory controller of the CPU
234 and add some more NUMA awareness to the kernel.
235 This code is recommended on all multiprocessor Opteron systems
236 and normally doesn't hurt on others.
239 bool "NUMA emulation support"
243 Enable NUMA emulation. A flat machine will be split
244 into virtual nodes when booted with "numa=fake=N", where N is the
245 number of nodes. This is only useful for debugging.
247 config ARCH_DISCONTIGMEM_ENABLE
256 config ARCH_DISCONTIGMEM_ENABLE
260 config ARCH_DISCONTIGMEM_DEFAULT
264 config ARCH_SPARSEMEM_ENABLE
268 config ARCH_FLATMEM_ENABLE
274 config HAVE_ARCH_EARLY_PFN_TO_NID
283 int "Maximum number of CPUs (2-256)"
288 This allows you to specify the maximum number of CPUs which this
289 kernel will support. Current maximum is 256 CPUs due to
290 APIC addressing limits. Less depending on the hardware.
292 This is purely to save memory - each supported CPU requires
293 memory in the static kernel configuration.
296 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
297 depends on SMP && HOTPLUG && EXPERIMENTAL
299 Say Y here to experiment with turning CPUs off and on. CPUs
300 can be controlled through /sys/devices/system/cpu/cpu#.
301 Say N if you want to disable CPU hotplug.
308 Use the IA-PC HPET (High Precision Event Timer) to manage
309 time in preference to the PIT and RTC, if a HPET is
310 present. The HPET provides a stable time base on SMP
311 systems, unlike the TSC, but it is more expensive to access,
312 as it is off-chip. You can find the HPET spec at
313 <http://www.intel.com/labs/platcomp/hpet/hpetspec.htm>.
320 Support the ACPI PM timer for time keeping. This is slow,
321 but is useful on some chipsets without HPET on systems with more
322 than one CPU. On a single processor or single socket multi core
323 system it is normally not required.
324 When the PM timer is active 64bit vsyscalls are disabled
325 and should not be enabled (/proc/sys/kernel/vsyscall64 should
327 The kernel selects the PM timer only as a last resort, so it is
328 useful to enable just in case.
330 config HPET_EMULATE_RTC
331 bool "Provide RTC interrupt"
332 depends on HPET_TIMER && RTC=y
339 Support the IOMMU. Needed to run systems with more than 3GB of memory
340 properly with 32-bit PCI devices that do not support DAC (Double Address
341 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
342 Normally the kernel will take the right choice by itself.
343 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
344 and a software emulation used on some other systems.
347 # need this always enabled with GART_IOMMU for the VIA workaround
350 depends on GART_IOMMU
355 depends on !GART_IOMMU && !SWIOTLB
358 Don't use IOMMU code. This will cause problems when you have more than 4GB
359 of memory and any 32-bit devices. Don't turn on unless you know what you
363 bool "Machine check support" if EMBEDDED
366 Include a machine check error handler to report hardware errors.
367 This version will require the mcelog utility to decode some
368 machine check error logs. See
369 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
372 bool "Intel MCE features"
373 depends on X86_MCE && X86_LOCAL_APIC
376 Additional support for intel specific MCE features such as
379 config PHYSICAL_START
380 hex "Physical address where the kernel is loaded" if EMBEDDED
383 This gives the physical address where the kernel is loaded.
384 Primarily used in the case of kexec on panic where the
385 fail safe kernel needs to run at a different address than
388 Don't change this unless you know what you are doing.
391 bool "kexec system call (EXPERIMENTAL)"
392 depends on EXPERIMENTAL
394 kexec is a system call that implements the ability to shutdown your
395 current kernel, and to start another kernel. It is like a reboot
396 but it is indepedent of the system firmware. And like a reboot
397 you can start any kernel with it, not just Linux.
399 The name comes from the similiarity to the exec system call.
401 It is an ongoing process to be certain the hardware in a machine
402 is properly shutdown, so do not be surprised if this code does not
403 initially work for you. It may help to enable device hotplugging
404 support. As of this writing the exact hardware interface is
405 strongly in flux, so no good recommendation can be made.
408 bool "Enable seccomp to safely compute untrusted bytecode"
412 This kernel feature is useful for number crunching applications
413 that may need to compute untrusted bytecode during their
414 execution. By using pipes or other transports made available to
415 the process as file descriptors supporting the read/write
416 syscalls, it's possible to isolate those applications in
417 their own address space using seccomp. Once seccomp is
418 enabled via /proc/<pid>/seccomp, it cannot be disabled
419 and the task is only allowed to execute a few safe syscalls
420 defined by each seccomp mode.
422 If unsure, say Y. Only embedded should say N here.
424 source kernel/Kconfig.hz
429 # Use the generic interrupt handling code in kernel/irq/:
431 config GENERIC_HARDIRQS
435 config GENERIC_IRQ_PROBE
439 # we have no ISA slots, but we do have ISA-style DMA.
444 config GENERIC_PENDING_IRQ
446 depends on GENERIC_HARDIRQS && SMP
449 menu "Power management options"
451 source kernel/power/Kconfig
453 source "drivers/acpi/Kconfig"
455 source "arch/x86_64/kernel/cpufreq/Kconfig"
459 menu "Bus options (PCI etc.)"
464 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
471 bool "Support mmconfig PCI config space access"
472 depends on PCI && ACPI
476 bool "Unordered IO mapping access"
477 depends on EXPERIMENTAL
479 Use unordered stores to access IO memory mappings in device drivers.
480 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
481 work with this option, but it makes the drivers behave differently
482 from i386. Requires that the driver writer used memory barriers
485 source "drivers/pci/pcie/Kconfig"
487 source "drivers/pci/Kconfig"
489 source "drivers/pcmcia/Kconfig"
491 source "drivers/pci/hotplug/Kconfig"
496 menu "Executable file formats / Emulations"
498 source "fs/Kconfig.binfmt"
500 config IA32_EMULATION
501 bool "IA32 Emulation"
503 Include code to run 32-bit programs under a 64-bit kernel. You should likely
504 turn this on, unless you're 100% sure that you don't have any 32-bit programs
508 bool "IA32 a.out support"
509 depends on IA32_EMULATION
511 Support old a.out binaries in the 32bit emulation.
515 depends on IA32_EMULATION
518 config SYSVIPC_COMPAT
520 depends on COMPAT && SYSVIPC
525 depends on IA32_EMULATION
532 source drivers/Kconfig
534 source "drivers/firmware/Kconfig"
538 source "arch/x86_64/oprofile/Kconfig"
540 source "arch/x86_64/Kconfig.debug"
542 source "security/Kconfig"
544 source "crypto/Kconfig"