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
155 # disable it for opteron optimized builds because it pulls in ACPI_BOOT
158 depends on SMP && !MK8
161 config MATH_EMULATION
174 config X86_LOCAL_APIC
179 bool "MTRR (Memory Type Range Register) support"
181 On Intel P6 family processors (Pentium Pro, Pentium II and later)
182 the Memory Type Range Registers (MTRRs) may be used to control
183 processor access to memory ranges. This is most useful if you have
184 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
185 allows bus write transfers to be combined into a larger transfer
186 before bursting over the PCI/AGP bus. This can increase performance
187 of image write operations 2.5 times or more. Saying Y here creates a
188 /proc/mtrr file which may be used to manipulate your processor's
189 MTRRs. Typically the X server should use this.
191 This code has a reasonably generic interface so that similar
192 control registers on other processors can be easily supported
195 Saying Y here also fixes a problem with buggy SMP BIOSes which only
196 set the MTRRs for the boot CPU and not for the secondary CPUs. This
197 can lead to all sorts of problems, so it's good to say Y here.
199 Just say Y here, all x86-64 machines support MTRRs.
201 See <file:Documentation/mtrr.txt> for more information.
204 bool "Symmetric multi-processing support"
206 This enables support for systems with more than one CPU. If you have
207 a system with only one CPU, like most personal computers, say N. If
208 you have a system with more than one CPU, say Y.
210 If you say N here, the kernel will run on single and multiprocessor
211 machines, but will use only one CPU of a multiprocessor machine. If
212 you say Y here, the kernel will run on many, but not all,
213 singleprocessor machines. On a singleprocessor machine, the kernel
214 will run faster if you say N here.
216 If you don't know what to do here, say N.
219 bool "SMT (Hyperthreading) scheduler support"
223 SMT scheduler support improves the CPU scheduler's decision making
224 when dealing with Intel Pentium 4 chips with HyperThreading at a
225 cost of slightly increased overhead in some places. If unsure say
228 source "kernel/Kconfig.preempt"
231 bool "K8 NUMA support"
235 Enable NUMA (Non Unified Memory Architecture) support for
236 AMD Opteron Multiprocessor systems. The kernel will try to allocate
237 memory used by a CPU on the local memory controller of the CPU
238 and add some more NUMA awareness to the kernel.
239 This code is recommended on all multiprocessor Opteron systems
240 and normally doesn't hurt on others.
243 bool "NUMA emulation support"
247 Enable NUMA emulation. A flat machine will be split
248 into virtual nodes when booted with "numa=fake=N", where N is the
249 number of nodes. This is only useful for debugging.
251 config ARCH_DISCONTIGMEM_ENABLE
260 config ARCH_DISCONTIGMEM_ENABLE
264 config ARCH_DISCONTIGMEM_DEFAULT
268 config ARCH_SPARSEMEM_ENABLE
272 config ARCH_FLATMEM_ENABLE
278 config HAVE_ARCH_EARLY_PFN_TO_NID
287 int "Maximum number of CPUs (2-256)"
292 This allows you to specify the maximum number of CPUs which this
293 kernel will support. Current maximum is 256 CPUs due to
294 APIC addressing limits. Less depending on the hardware.
296 This is purely to save memory - each supported CPU requires
297 memory in the static kernel configuration.
300 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
301 depends on SMP && HOTPLUG && EXPERIMENTAL
303 Say Y here to experiment with turning CPUs off and on. CPUs
304 can be controlled through /sys/devices/system/cpu/cpu#.
305 Say N if you want to disable CPU hotplug.
312 Use the IA-PC HPET (High Precision Event Timer) to manage
313 time in preference to the PIT and RTC, if a HPET is
314 present. The HPET provides a stable time base on SMP
315 systems, unlike the TSC, but it is more expensive to access,
316 as it is off-chip. You can find the HPET spec at
317 <http://www.intel.com/labs/platcomp/hpet/hpetspec.htm>.
324 Support the ACPI PM timer for time keeping. This is slow,
325 but is useful on some chipsets without HPET on systems with more
326 than one CPU. On a single processor or single socket multi core
327 system it is normally not required.
328 When the PM timer is active 64bit vsyscalls are disabled
329 and should not be enabled (/proc/sys/kernel/vsyscall64 should
331 The kernel selects the PM timer only as a last resort, so it is
332 useful to enable just in case.
334 config HPET_EMULATE_RTC
335 bool "Provide RTC interrupt"
336 depends on HPET_TIMER && RTC=y
343 Support the IOMMU. Needed to run systems with more than 3GB of memory
344 properly with 32-bit PCI devices that do not support DAC (Double Address
345 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
346 Normally the kernel will take the right choice by itself.
347 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
348 and a software emulation used on some other systems.
351 # need this always enabled with GART_IOMMU for the VIA workaround
354 depends on GART_IOMMU
359 depends on !GART_IOMMU && !SWIOTLB
362 Don't use IOMMU code. This will cause problems when you have more than 4GB
363 of memory and any 32-bit devices. Don't turn on unless you know what you
367 bool "Machine check support" if EMBEDDED
370 Include a machine check error handler to report hardware errors.
371 This version will require the mcelog utility to decode some
372 machine check error logs. See
373 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
376 bool "Intel MCE features"
377 depends on X86_MCE && X86_LOCAL_APIC
380 Additional support for intel specific MCE features such as
383 config PHYSICAL_START
384 hex "Physical address where the kernel is loaded" if EMBEDDED
387 This gives the physical address where the kernel is loaded.
388 Primarily used in the case of kexec on panic where the
389 fail safe kernel needs to run at a different address than
392 Don't change this unless you know what you are doing.
395 bool "kexec system call (EXPERIMENTAL)"
396 depends on EXPERIMENTAL
398 kexec is a system call that implements the ability to shutdown your
399 current kernel, and to start another kernel. It is like a reboot
400 but it is indepedent of the system firmware. And like a reboot
401 you can start any kernel with it, not just Linux.
403 The name comes from the similiarity to the exec system call.
405 It is an ongoing process to be certain the hardware in a machine
406 is properly shutdown, so do not be surprised if this code does not
407 initially work for you. It may help to enable device hotplugging
408 support. As of this writing the exact hardware interface is
409 strongly in flux, so no good recommendation can be made.
412 bool "Enable seccomp to safely compute untrusted bytecode"
416 This kernel feature is useful for number crunching applications
417 that may need to compute untrusted bytecode during their
418 execution. By using pipes or other transports made available to
419 the process as file descriptors supporting the read/write
420 syscalls, it's possible to isolate those applications in
421 their own address space using seccomp. Once seccomp is
422 enabled via /proc/<pid>/seccomp, it cannot be disabled
423 and the task is only allowed to execute a few safe syscalls
424 defined by each seccomp mode.
426 If unsure, say Y. Only embedded should say N here.
428 source kernel/Kconfig.hz
433 # Use the generic interrupt handling code in kernel/irq/:
435 config GENERIC_HARDIRQS
439 config GENERIC_IRQ_PROBE
443 # we have no ISA slots, but we do have ISA-style DMA.
448 config GENERIC_PENDING_IRQ
450 depends on GENERIC_HARDIRQS && SMP
453 menu "Power management options"
455 source kernel/power/Kconfig
457 source "drivers/acpi/Kconfig"
459 source "arch/x86_64/kernel/cpufreq/Kconfig"
463 menu "Bus options (PCI etc.)"
468 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
475 bool "Support mmconfig PCI config space access"
476 depends on PCI && ACPI
480 bool "Unordered IO mapping access"
481 depends on EXPERIMENTAL
483 Use unordered stores to access IO memory mappings in device drivers.
484 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
485 work with this option, but it makes the drivers behave differently
486 from i386. Requires that the driver writer used memory barriers
489 source "drivers/pci/pcie/Kconfig"
491 source "drivers/pci/Kconfig"
493 source "drivers/pcmcia/Kconfig"
495 source "drivers/pci/hotplug/Kconfig"
500 menu "Executable file formats / Emulations"
502 source "fs/Kconfig.binfmt"
504 config IA32_EMULATION
505 bool "IA32 Emulation"
507 Include code to run 32-bit programs under a 64-bit kernel. You should likely
508 turn this on, unless you're 100% sure that you don't have any 32-bit programs
512 bool "IA32 a.out support"
513 depends on IA32_EMULATION
515 Support old a.out binaries in the 32bit emulation.
519 depends on IA32_EMULATION
522 config SYSVIPC_COMPAT
524 depends on COMPAT && SYSVIPC
529 depends on IA32_EMULATION
536 source drivers/Kconfig
538 source "drivers/firmware/Kconfig"
542 source "arch/x86_64/oprofile/Kconfig"
544 source "arch/x86_64/Kconfig.debug"
546 source "security/Kconfig"
548 source "crypto/Kconfig"