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 LOCKDEP_SUPPORT
31 config STACKTRACE_SUPPORT
35 config SEMAPHORE_SLEEPERS
49 config RWSEM_GENERIC_SPINLOCK
53 config RWSEM_XCHGADD_ALGORITHM
56 config GENERIC_HWEIGHT
60 config GENERIC_CALIBRATE_DELAY
72 config GENERIC_ISA_DMA
80 config ARCH_MAY_HAVE_PC_FDC
91 menu "Processor type and features"
94 prompt "Subarchitecture Type"
100 Choose this option if your computer is a standard PC or compatible.
103 bool "Support for ScaleMP vSMP"
105 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
106 supposed to run on these EM64T-based machines. Only choose this option
107 if you have one of these machines.
112 prompt "Processor family"
116 bool "AMD-Opteron/Athlon64"
118 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
123 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
124 Extended Memory 64 Technology(EM64T). For details see
125 <http://www.intel.com/technology/64bitextensions/>.
128 bool "Generic-x86-64"
135 # Define implied options from the CPU selection here
137 config X86_L1_CACHE_BYTES
139 default "128" if GENERIC_CPU || MPSC
142 config X86_L1_CACHE_SHIFT
144 default "7" if GENERIC_CPU || MPSC
147 config X86_INTERNODE_CACHE_BYTES
149 default "4096" if X86_VSMP
150 default X86_L1_CACHE_BYTES if !X86_VSMP
161 tristate "/dev/cpu/microcode - Intel CPU microcode support"
163 If you say Y here the 'File systems' section, you will be
164 able to update the microcode on Intel processors. You will
165 obviously need the actual microcode binary data itself which is
166 not shipped with the Linux kernel.
168 For latest news and information on obtaining all the required
169 ingredients for this driver, check:
170 <http://www.urbanmyth.org/microcode/>.
172 To compile this driver as a module, choose M here: the
173 module will be called microcode.
174 If you use modprobe or kmod you may also want to add the line
175 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
178 tristate "/dev/cpu/*/msr - Model-specific register support"
180 This device gives privileged processes access to the x86
181 Model-Specific Registers (MSRs). It is a character device with
182 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
183 MSR accesses are directed to a specific CPU on multi-processor
187 tristate "/dev/cpu/*/cpuid - CPU information support"
189 This device gives processes access to the x86 CPUID instruction to
190 be executed on a specific processor. It is a character device
191 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
196 depends on SMP && !MK8
199 config MATH_EMULATION
212 config X86_LOCAL_APIC
217 bool "MTRR (Memory Type Range Register) support"
219 On Intel P6 family processors (Pentium Pro, Pentium II and later)
220 the Memory Type Range Registers (MTRRs) may be used to control
221 processor access to memory ranges. This is most useful if you have
222 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
223 allows bus write transfers to be combined into a larger transfer
224 before bursting over the PCI/AGP bus. This can increase performance
225 of image write operations 2.5 times or more. Saying Y here creates a
226 /proc/mtrr file which may be used to manipulate your processor's
227 MTRRs. Typically the X server should use this.
229 This code has a reasonably generic interface so that similar
230 control registers on other processors can be easily supported
233 Saying Y here also fixes a problem with buggy SMP BIOSes which only
234 set the MTRRs for the boot CPU and not for the secondary CPUs. This
235 can lead to all sorts of problems, so it's good to say Y here.
237 Just say Y here, all x86-64 machines support MTRRs.
239 See <file:Documentation/mtrr.txt> for more information.
242 bool "Symmetric multi-processing support"
244 This enables support for systems with more than one CPU. If you have
245 a system with only one CPU, like most personal computers, say N. If
246 you have a system with more than one CPU, say Y.
248 If you say N here, the kernel will run on single and multiprocessor
249 machines, but will use only one CPU of a multiprocessor machine. If
250 you say Y here, the kernel will run on many, but not all,
251 singleprocessor machines. On a singleprocessor machine, the kernel
252 will run faster if you say N here.
254 If you don't know what to do here, say N.
257 bool "SMT (Hyperthreading) scheduler support"
261 SMT scheduler support improves the CPU scheduler's decision making
262 when dealing with Intel Pentium 4 chips with HyperThreading at a
263 cost of slightly increased overhead in some places. If unsure say
267 bool "Multi-core scheduler support"
271 Multi-core scheduler support improves the CPU scheduler's decision
272 making when dealing with multi-core CPU chips at a cost of slightly
273 increased overhead in some places. If unsure say N here.
275 source "kernel/Kconfig.preempt"
278 bool "Non Uniform Memory Access (NUMA) Support"
281 Enable NUMA (Non Uniform Memory Access) support. The kernel
282 will try to allocate memory used by a CPU on the local memory
283 controller of the CPU and add some more NUMA awareness to the kernel.
284 This code is recommended on all multiprocessor Opteron systems.
285 If the system is EM64T, you should say N unless your system is EM64T
289 bool "Old style AMD Opteron NUMA detection"
293 Enable K8 NUMA node topology detection. You should say Y here if
294 you have a multi processor AMD K8 system. This uses an old
295 method to read the NUMA configurtion directly from the builtin
296 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
297 instead, which also takes priority if both are compiled in.
302 depends on NEED_MULTIPLE_NODES
304 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
306 config X86_64_ACPI_NUMA
307 bool "ACPI NUMA detection"
314 Enable ACPI SRAT based node topology detection.
317 bool "NUMA emulation"
320 Enable NUMA emulation. A flat machine will be split
321 into virtual nodes when booted with "numa=fake=N", where N is the
322 number of nodes. This is only useful for debugging.
324 config ARCH_DISCONTIGMEM_ENABLE
330 config ARCH_DISCONTIGMEM_ENABLE
334 config ARCH_DISCONTIGMEM_DEFAULT
338 config ARCH_SPARSEMEM_ENABLE
340 depends on (NUMA || EXPERIMENTAL)
342 config ARCH_MEMORY_PROBE
344 depends on MEMORY_HOTPLUG
346 config ARCH_FLATMEM_ENABLE
352 config HAVE_ARCH_EARLY_PFN_TO_NID
356 config OUT_OF_LINE_PFN_TO_PAGE
358 depends on DISCONTIGMEM
361 int "Maximum number of CPUs (2-256)"
366 This allows you to specify the maximum number of CPUs which this
367 kernel will support. Current maximum is 256 CPUs due to
368 APIC addressing limits. Less depending on the hardware.
370 This is purely to save memory - each supported CPU requires
371 memory in the static kernel configuration.
374 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
375 depends on SMP && HOTPLUG && EXPERIMENTAL
377 Say Y here to experiment with turning CPUs off and on. CPUs
378 can be controlled through /sys/devices/system/cpu/cpu#.
379 Say N if you want to disable CPU hotplug.
381 config ARCH_ENABLE_MEMORY_HOTPLUG
388 Use the IA-PC HPET (High Precision Event Timer) to manage
389 time in preference to the PIT and RTC, if a HPET is
390 present. The HPET provides a stable time base on SMP
391 systems, unlike the TSC, but it is more expensive to access,
392 as it is off-chip. You can find the HPET spec at
393 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
395 config HPET_EMULATE_RTC
396 bool "Provide RTC interrupt"
397 depends on HPET_TIMER && RTC=y
399 # Mark as embedded because too many people got it wrong.
400 # The code disables itself when not needed.
402 bool "IOMMU support" if EMBEDDED
408 Support for full DMA access of devices with 32bit memory access only
409 on systems with more than 3GB. This is usually needed for USB,
410 sound, many IDE/SATA chipsets and some other devices.
411 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
412 based IOMMU and a software bounce buffer based IOMMU used on Intel
413 systems and as fallback.
414 The code is only active when needed (enough memory and limited
415 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
419 bool "IBM Calgary IOMMU support"
422 depends on PCI && EXPERIMENTAL
424 Support for hardware IOMMUs in IBM's xSeries x366 and x460
425 systems. Needed to run systems with more than 3GB of memory
426 properly with 32-bit PCI devices that do not support DAC
427 (Double Address Cycle). Calgary also supports bus level
428 isolation, where all DMAs pass through the IOMMU. This
429 prevents them from going anywhere except their intended
430 destination. This catches hard-to-find kernel bugs and
431 mis-behaving drivers and devices that do not use the DMA-API
432 properly to set up their DMA buffers. The IOMMU can be
433 turned off at boot time with the iommu=off parameter.
434 Normally the kernel will make the right choice by itself.
437 # need this always selected by IOMMU for the VIA workaround
442 bool "Machine check support" if EMBEDDED
445 Include a machine check error handler to report hardware errors.
446 This version will require the mcelog utility to decode some
447 machine check error logs. See
448 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
451 bool "Intel MCE features"
452 depends on X86_MCE && X86_LOCAL_APIC
455 Additional support for intel specific MCE features such as
459 bool "AMD MCE features"
460 depends on X86_MCE && X86_LOCAL_APIC
463 Additional support for AMD specific MCE features such as
464 the DRAM Error Threshold.
467 bool "kexec system call (EXPERIMENTAL)"
468 depends on EXPERIMENTAL
470 kexec is a system call that implements the ability to shutdown your
471 current kernel, and to start another kernel. It is like a reboot
472 but it is independent of the system firmware. And like a reboot
473 you can start any kernel with it, not just Linux.
475 The name comes from the similarity to the exec system call.
477 It is an ongoing process to be certain the hardware in a machine
478 is properly shutdown, so do not be surprised if this code does not
479 initially work for you. It may help to enable device hotplugging
480 support. As of this writing the exact hardware interface is
481 strongly in flux, so no good recommendation can be made.
484 bool "kernel crash dumps (EXPERIMENTAL)"
485 depends on EXPERIMENTAL
487 Generate crash dump after being started by kexec.
489 config PHYSICAL_START
490 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
491 default "0x1000000" if CRASH_DUMP
494 This gives the physical address where the kernel is loaded. Normally
495 for regular kernels this value is 0x200000 (2MB). But in the case
496 of kexec on panic the fail safe kernel needs to run at a different
497 address than the panic-ed kernel. This option is used to set the load
498 address for kernels used to capture crash dump on being kexec'ed
499 after panic. The default value for crash dump kernels is
500 0x1000000 (16MB). This can also be set based on the "X" value as
501 specified in the "crashkernel=YM@XM" command line boot parameter
502 passed to the panic-ed kernel. Typically this parameter is set as
503 crashkernel=64M@16M. Please take a look at
504 Documentation/kdump/kdump.txt for more details about crash dumps.
506 Don't change this unless you know what you are doing.
509 bool "Enable seccomp to safely compute untrusted bytecode"
513 This kernel feature is useful for number crunching applications
514 that may need to compute untrusted bytecode during their
515 execution. By using pipes or other transports made available to
516 the process as file descriptors supporting the read/write
517 syscalls, it's possible to isolate those applications in
518 their own address space using seccomp. Once seccomp is
519 enabled via /proc/<pid>/seccomp, it cannot be disabled
520 and the task is only allowed to execute a few safe syscalls
521 defined by each seccomp mode.
523 If unsure, say Y. Only embedded should say N here.
525 source kernel/Kconfig.hz
528 bool "Function reordering"
531 This option enables the toolchain to reorder functions for a more
532 optimal TLB usage. If you have pretty much any version of binutils,
533 this can increase your kernel build time by roughly one minute.
537 depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
542 # Use the generic interrupt handling code in kernel/irq/:
544 config GENERIC_HARDIRQS
548 config GENERIC_IRQ_PROBE
552 # we have no ISA slots, but we do have ISA-style DMA.
557 config GENERIC_PENDING_IRQ
559 depends on GENERIC_HARDIRQS && SMP
562 menu "Power management options"
564 source kernel/power/Kconfig
566 source "drivers/acpi/Kconfig"
568 source "arch/x86_64/kernel/cpufreq/Kconfig"
572 menu "Bus options (PCI etc.)"
577 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
584 bool "Support mmconfig PCI config space access"
585 depends on PCI && ACPI
587 source "drivers/pci/pcie/Kconfig"
589 source "drivers/pci/Kconfig"
591 source "drivers/pcmcia/Kconfig"
593 source "drivers/pci/hotplug/Kconfig"
598 menu "Executable file formats / Emulations"
600 source "fs/Kconfig.binfmt"
602 config IA32_EMULATION
603 bool "IA32 Emulation"
605 Include code to run 32-bit programs under a 64-bit kernel. You should likely
606 turn this on, unless you're 100% sure that you don't have any 32-bit programs
610 tristate "IA32 a.out support"
611 depends on IA32_EMULATION
613 Support old a.out binaries in the 32bit emulation.
617 depends on IA32_EMULATION
620 config SYSVIPC_COMPAT
622 depends on COMPAT && SYSVIPC
629 source drivers/Kconfig
631 source "drivers/firmware/Kconfig"
635 menu "Instrumentation Support"
636 depends on EXPERIMENTAL
638 source "arch/x86_64/oprofile/Kconfig"
641 bool "Kprobes (EXPERIMENTAL)"
642 depends on EXPERIMENTAL && MODULES
644 Kprobes allows you to trap at almost any kernel address and
645 execute a callback function. register_kprobe() establishes
646 a probepoint and specifies the callback. Kprobes is useful
647 for kernel debugging, non-intrusive instrumentation and testing.
648 If in doubt, say "N".
651 source "arch/x86_64/Kconfig.debug"
653 source "security/Kconfig"
655 source "crypto/Kconfig"