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
147 # disable it for opteron optimized builds because it pulls in ACPI_BOOT
150 depends on SMP && !MK8
153 config MATH_EMULATION
166 config X86_LOCAL_APIC
171 bool "MTRR (Memory Type Range Register) support"
173 On Intel P6 family processors (Pentium Pro, Pentium II and later)
174 the Memory Type Range Registers (MTRRs) may be used to control
175 processor access to memory ranges. This is most useful if you have
176 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
177 allows bus write transfers to be combined into a larger transfer
178 before bursting over the PCI/AGP bus. This can increase performance
179 of image write operations 2.5 times or more. Saying Y here creates a
180 /proc/mtrr file which may be used to manipulate your processor's
181 MTRRs. Typically the X server should use this.
183 This code has a reasonably generic interface so that similar
184 control registers on other processors can be easily supported
187 Saying Y here also fixes a problem with buggy SMP BIOSes which only
188 set the MTRRs for the boot CPU and not for the secondary CPUs. This
189 can lead to all sorts of problems, so it's good to say Y here.
191 Just say Y here, all x86-64 machines support MTRRs.
193 See <file:Documentation/mtrr.txt> for more information.
196 bool "Symmetric multi-processing support"
198 This enables support for systems with more than one CPU. If you have
199 a system with only one CPU, like most personal computers, say N. If
200 you have a system with more than one CPU, say Y.
202 If you say N here, the kernel will run on single and multiprocessor
203 machines, but will use only one CPU of a multiprocessor machine. If
204 you say Y here, the kernel will run on many, but not all,
205 singleprocessor machines. On a singleprocessor machine, the kernel
206 will run faster if you say N here.
208 If you don't know what to do here, say N.
211 bool "SMT (Hyperthreading) scheduler support"
215 SMT scheduler support improves the CPU scheduler's decision making
216 when dealing with Intel Pentium 4 chips with HyperThreading at a
217 cost of slightly increased overhead in some places. If unsure say
220 source "kernel/Kconfig.preempt"
223 bool "K8 NUMA support"
227 Enable NUMA (Non Unified Memory Architecture) support for
228 AMD Opteron Multiprocessor systems. The kernel will try to allocate
229 memory used by a CPU on the local memory controller of the CPU
230 and add some more NUMA awareness to the kernel.
231 This code is recommended on all multiprocessor Opteron systems
232 and normally doesn't hurt on others.
235 bool "NUMA emulation support"
239 Enable NUMA emulation. A flat machine will be split
240 into virtual nodes when booted with "numa=fake=N", where N is the
241 number of nodes. This is only useful for debugging.
243 config ARCH_DISCONTIGMEM_ENABLE
252 config ARCH_DISCONTIGMEM_ENABLE
256 config ARCH_DISCONTIGMEM_DEFAULT
260 config ARCH_SPARSEMEM_ENABLE
264 config ARCH_FLATMEM_ENABLE
270 config HAVE_ARCH_EARLY_PFN_TO_NID
279 int "Maximum number of CPUs (2-256)"
284 This allows you to specify the maximum number of CPUs which this
285 kernel will support. Current maximum is 256 CPUs due to
286 APIC addressing limits. Less depending on the hardware.
288 This is purely to save memory - each supported CPU requires
289 memory in the static kernel configuration.
292 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
293 depends on SMP && HOTPLUG && EXPERIMENTAL
295 Say Y here to experiment with turning CPUs off and on. CPUs
296 can be controlled through /sys/devices/system/cpu/cpu#.
297 Say N if you want to disable CPU hotplug.
304 Use the IA-PC HPET (High Precision Event Timer) to manage
305 time in preference to the PIT and RTC, if a HPET is
306 present. The HPET provides a stable time base on SMP
307 systems, unlike the TSC, but it is more expensive to access,
308 as it is off-chip. You can find the HPET spec at
309 <http://www.intel.com/labs/platcomp/hpet/hpetspec.htm>.
316 Support the ACPI PM timer for time keeping. This is slow,
317 but is useful on some chipsets without HPET on systems with more
318 than one CPU. On a single processor or single socket multi core
319 system it is normally not required.
320 When the PM timer is active 64bit vsyscalls are disabled
321 and should not be enabled (/proc/sys/kernel/vsyscall64 should
323 The kernel selects the PM timer only as a last resort, so it is
324 useful to enable just in case.
326 config HPET_EMULATE_RTC
327 bool "Provide RTC interrupt"
328 depends on HPET_TIMER && RTC=y
335 Support the IOMMU. Needed to run systems with more than 3GB of memory
336 properly with 32-bit PCI devices that do not support DAC (Double Address
337 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
338 Normally the kernel will take the right choice by itself.
339 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
340 and a software emulation used on some other systems.
343 # need this always enabled with GART_IOMMU for the VIA workaround
346 depends on GART_IOMMU
351 depends on !GART_IOMMU && !SWIOTLB
354 Don't use IOMMU code. This will cause problems when you have more than 4GB
355 of memory and any 32-bit devices. Don't turn on unless you know what you
359 bool "Machine check support" if EMBEDDED
362 Include a machine check error handler to report hardware errors.
363 This version will require the mcelog utility to decode some
364 machine check error logs. See
365 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
368 bool "Intel MCE features"
369 depends on X86_MCE && X86_LOCAL_APIC
372 Additional support for intel specific MCE features such as
375 config PHYSICAL_START
376 hex "Physical address where the kernel is loaded" if EMBEDDED
379 This gives the physical address where the kernel is loaded.
380 Primarily used in the case of kexec on panic where the
381 fail safe kernel needs to run at a different address than
384 Don't change this unless you know what you are doing.
387 bool "kexec system call (EXPERIMENTAL)"
388 depends on EXPERIMENTAL
390 kexec is a system call that implements the ability to shutdown your
391 current kernel, and to start another kernel. It is like a reboot
392 but it is indepedent of the system firmware. And like a reboot
393 you can start any kernel with it, not just Linux.
395 The name comes from the similiarity to the exec system call.
397 It is an ongoing process to be certain the hardware in a machine
398 is properly shutdown, so do not be surprised if this code does not
399 initially work for you. It may help to enable device hotplugging
400 support. As of this writing the exact hardware interface is
401 strongly in flux, so no good recommendation can be made.
404 bool "Enable seccomp to safely compute untrusted bytecode"
408 This kernel feature is useful for number crunching applications
409 that may need to compute untrusted bytecode during their
410 execution. By using pipes or other transports made available to
411 the process as file descriptors supporting the read/write
412 syscalls, it's possible to isolate those applications in
413 their own address space using seccomp. Once seccomp is
414 enabled via /proc/<pid>/seccomp, it cannot be disabled
415 and the task is only allowed to execute a few safe syscalls
416 defined by each seccomp mode.
418 If unsure, say Y. Only embedded should say N here.
420 source kernel/Kconfig.hz
425 # Use the generic interrupt handling code in kernel/irq/:
427 config GENERIC_HARDIRQS
431 config GENERIC_IRQ_PROBE
435 # we have no ISA slots, but we do have ISA-style DMA.
440 menu "Power management options"
442 source kernel/power/Kconfig
444 source "drivers/acpi/Kconfig"
446 source "arch/x86_64/kernel/cpufreq/Kconfig"
450 menu "Bus options (PCI etc.)"
455 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
462 bool "Support mmconfig PCI config space access"
463 depends on PCI && ACPI
467 bool "Unordered IO mapping access"
468 depends on EXPERIMENTAL
470 Use unordered stores to access IO memory mappings in device drivers.
471 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
472 work with this option, but it makes the drivers behave differently
473 from i386. Requires that the driver writer used memory barriers
476 source "drivers/pci/pcie/Kconfig"
478 source "drivers/pci/Kconfig"
480 source "drivers/pcmcia/Kconfig"
482 source "drivers/pci/hotplug/Kconfig"
487 menu "Executable file formats / Emulations"
489 source "fs/Kconfig.binfmt"
491 config IA32_EMULATION
492 bool "IA32 Emulation"
494 Include code to run 32-bit programs under a 64-bit kernel. You should likely
495 turn this on, unless you're 100% sure that you don't have any 32-bit programs
499 bool "IA32 a.out support"
500 depends on IA32_EMULATION
502 Support old a.out binaries in the 32bit emulation.
506 depends on IA32_EMULATION
509 config SYSVIPC_COMPAT
511 depends on COMPAT && SYSVIPC
516 depends on IA32_EMULATION
523 source drivers/Kconfig
525 source "drivers/firmware/Kconfig"
529 source "arch/x86_64/oprofile/Kconfig"
531 source "arch/x86_64/Kconfig.debug"
533 source "security/Kconfig"
535 source "crypto/Kconfig"