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_HWEIGHT
52 config GENERIC_CALIBRATE_DELAY
64 config GENERIC_ISA_DMA
72 config ARCH_MAY_HAVE_PC_FDC
83 menu "Processor type and features"
86 prompt "Subarchitecture Type"
92 Choose this option if your computer is a standard PC or compatible.
95 bool "Support for ScaleMP vSMP"
97 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
98 supposed to run on these EM64T-based machines. Only choose this option
99 if you have one of these machines.
104 prompt "Processor family"
108 bool "AMD-Opteron/Athlon64"
110 Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
115 Optimize for Intel Pentium 4 and Xeon CPUs with Intel
116 Extended Memory 64 Technology(EM64T). For details see
117 <http://www.intel.com/technology/64bitextensions/>.
120 bool "Generic-x86-64"
127 bool "Enable Xen compatible kernel"
130 This option will compile a kernel compatible with Xen hypervisor
134 depends on X86_64_XEN
139 depends on X86_64_XEN
143 # Define implied options from the CPU selection here
145 config X86_L1_CACHE_BYTES
147 default "128" if GENERIC_CPU || MPSC
150 config X86_L1_CACHE_SHIFT
152 default "7" if GENERIC_CPU || MPSC
155 config X86_INTERNODE_CACHE_BYTES
157 default "4096" if X86_VSMP
158 default X86_L1_CACHE_BYTES if !X86_VSMP
162 depends on !X86_64_XEN
170 tristate "/dev/cpu/microcode - Intel CPU microcode support"
172 If you say Y here the 'File systems' section, you will be
173 able to update the microcode on Intel processors. You will
174 obviously need the actual microcode binary data itself which is
175 not shipped with the Linux kernel.
177 For latest news and information on obtaining all the required
178 ingredients for this driver, check:
179 <http://www.urbanmyth.org/microcode/>.
181 To compile this driver as a module, choose M here: the
182 module will be called microcode.
183 If you use modprobe or kmod you may also want to add the line
184 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
187 tristate "/dev/cpu/*/msr - Model-specific register support"
189 This device gives privileged processes access to the x86
190 Model-Specific Registers (MSRs). It is a character device with
191 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
192 MSR accesses are directed to a specific CPU on multi-processor
196 tristate "/dev/cpu/*/cpuid - CPU information support"
198 This device gives processes access to the x86 CPUID instruction to
199 be executed on a specific processor. It is a character device
200 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
205 depends on SMP && !MK8 && !X86_64_XEN
208 config MATH_EMULATION
219 depends !XEN_UNPRIVILEGED_GUEST
222 config X86_XEN_GENAPIC
225 default XEN_PRIVILEGED_GUEST || SMP
227 config X86_LOCAL_APIC
229 depends !XEN_UNPRIVILEGED_GUEST
233 bool "MTRR (Memory Type Range Register) support"
234 depends on !XEN_UNPRIVILEGED_GUEST
236 On Intel P6 family processors (Pentium Pro, Pentium II and later)
237 the Memory Type Range Registers (MTRRs) may be used to control
238 processor access to memory ranges. This is most useful if you have
239 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
240 allows bus write transfers to be combined into a larger transfer
241 before bursting over the PCI/AGP bus. This can increase performance
242 of image write operations 2.5 times or more. Saying Y here creates a
243 /proc/mtrr file which may be used to manipulate your processor's
244 MTRRs. Typically the X server should use this.
246 This code has a reasonably generic interface so that similar
247 control registers on other processors can be easily supported
250 Saying Y here also fixes a problem with buggy SMP BIOSes which only
251 set the MTRRs for the boot CPU and not for the secondary CPUs. This
252 can lead to all sorts of problems, so it's good to say Y here.
254 Just say Y here, all x86-64 machines support MTRRs.
256 See <file:Documentation/mtrr.txt> for more information.
259 bool "Symmetric multi-processing support"
261 This enables support for systems with more than one CPU. If you have
262 a system with only one CPU, like most personal computers, say N. If
263 you have a system with more than one CPU, say Y.
265 If you say N here, the kernel will run on single and multiprocessor
266 machines, but will use only one CPU of a multiprocessor machine. If
267 you say Y here, the kernel will run on many, but not all,
268 singleprocessor machines. On a singleprocessor machine, the kernel
269 will run faster if you say N here.
271 If you don't know what to do here, say N.
274 bool "SMT (Hyperthreading) scheduler support"
275 depends on SMP && !X86_64_XEN
278 SMT scheduler support improves the CPU scheduler's decision making
279 when dealing with Intel Pentium 4 chips with HyperThreading at a
280 cost of slightly increased overhead in some places. If unsure say
284 bool "Multi-core scheduler support"
285 depends on SMP && !X86_64_XEN
288 Multi-core scheduler support improves the CPU scheduler's decision
289 making when dealing with multi-core CPU chips at a cost of slightly
290 increased overhead in some places. If unsure say N here.
292 source "kernel/Kconfig.preempt"
295 bool "Non Uniform Memory Access (NUMA) Support"
296 depends on SMP && !X86_64_XEN
298 Enable NUMA (Non Uniform Memory Access) support. The kernel
299 will try to allocate memory used by a CPU on the local memory
300 controller of the CPU and add some more NUMA awareness to the kernel.
301 This code is recommended on all multiprocessor Opteron systems.
302 If the system is EM64T, you should say N unless your system is EM64T
306 bool "Old style AMD Opteron NUMA detection"
310 Enable K8 NUMA node topology detection. You should say Y here if
311 you have a multi processor AMD K8 system. This uses an old
312 method to read the NUMA configurtion directly from the builtin
313 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
314 instead, which also takes priority if both are compiled in.
319 depends on NEED_MULTIPLE_NODES
321 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
323 config X86_64_ACPI_NUMA
324 bool "ACPI NUMA detection"
330 Enable ACPI SRAT based node topology detection.
333 bool "NUMA emulation"
336 Enable NUMA emulation. A flat machine will be split
337 into virtual nodes when booted with "numa=fake=N", where N is the
338 number of nodes. This is only useful for debugging.
340 config ARCH_DISCONTIGMEM_ENABLE
346 config ARCH_DISCONTIGMEM_ENABLE
350 config ARCH_DISCONTIGMEM_DEFAULT
354 config ARCH_SPARSEMEM_ENABLE
356 depends on (NUMA || EXPERIMENTAL) && !X86_64_XEN
358 config ARCH_MEMORY_PROBE
360 depends on MEMORY_HOTPLUG
362 config ARCH_FLATMEM_ENABLE
368 config HAVE_ARCH_EARLY_PFN_TO_NID
372 config OUT_OF_LINE_PFN_TO_PAGE
374 depends on DISCONTIGMEM
377 int "Maximum number of CPUs (2-256)"
380 default "16" if X86_64_XEN
383 This allows you to specify the maximum number of CPUs which this
384 kernel will support. Current maximum is 256 CPUs due to
385 APIC addressing limits. Less depending on the hardware.
387 This is purely to save memory - each supported CPU requires
388 memory in the static kernel configuration.
391 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
392 depends on SMP && HOTPLUG && EXPERIMENTAL
394 Say Y here to experiment with turning CPUs off and on. CPUs
395 can be controlled through /sys/devices/system/cpu/cpu#.
396 Say N if you want to disable CPU hotplug.
398 config ARCH_ENABLE_MEMORY_HOTPLUG
403 depends on !X86_64_XEN
406 Use the IA-PC HPET (High Precision Event Timer) to manage
407 time in preference to the PIT and RTC, if a HPET is
408 present. The HPET provides a stable time base on SMP
409 systems, unlike the TSC, but it is more expensive to access,
410 as it is off-chip. You can find the HPET spec at
411 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
413 config HPET_EMULATE_RTC
414 bool "Provide RTC interrupt"
415 depends on HPET_TIMER && RTC=y
418 bool "K8 GART IOMMU support"
421 depends on PCI && !X86_64_XEN
423 Support for hardware IOMMU in AMD's Opteron/Athlon64 Processors
424 and for the bounce buffering software IOMMU.
425 Needed to run systems with more than 3GB of memory properly with
426 32-bit PCI devices that do not support DAC (Double Address Cycle).
427 The IOMMU can be turned off at runtime with the iommu=off parameter.
428 Normally the kernel will take the right choice by itself.
429 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
430 northbridge and a software emulation used on other systems without
431 hardware IOMMU. If unsure, say Y.
433 # need this always enabled with GART_IOMMU for the VIA workaround
437 depends on GART_IOMMU
440 bool "Machine check support" if EMBEDDED
441 depends on !X86_64_XEN
444 Include a machine check error handler to report hardware errors.
445 This version will require the mcelog utility to decode some
446 machine check error logs. See
447 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
450 bool "Intel MCE features"
451 depends on X86_MCE && X86_LOCAL_APIC
454 Additional support for intel specific MCE features such as
458 bool "AMD MCE features"
459 depends on X86_MCE && X86_LOCAL_APIC
462 Additional support for AMD specific MCE features such as
463 the DRAM Error Threshold.
466 bool "kexec system call (EXPERIMENTAL)"
467 depends on EXPERIMENTAL && !X86_64_XEN
469 kexec is a system call that implements the ability to shutdown your
470 current kernel, and to start another kernel. It is like a reboot
471 but it is indepedent of the system firmware. And like a reboot
472 you can start any kernel with it, not just Linux.
474 The name comes from the similiarity to the exec system call.
476 It is an ongoing process to be certain the hardware in a machine
477 is properly shutdown, so do not be surprised if this code does not
478 initially work for you. It may help to enable device hotplugging
479 support. As of this writing the exact hardware interface is
480 strongly in flux, so no good recommendation can be made.
483 bool "kernel crash dumps (EXPERIMENTAL)"
484 depends on EXPERIMENTAL
486 Generate crash dump after being started by kexec.
488 config PHYSICAL_START
489 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
490 default "0x1000000" if CRASH_DUMP
493 This gives the physical address where the kernel is loaded. Normally
494 for regular kernels this value is 0x200000 (2MB). But in the case
495 of kexec on panic the fail safe kernel needs to run at a different
496 address than the panic-ed kernel. This option is used to set the load
497 address for kernels used to capture crash dump on being kexec'ed
498 after panic. The default value for crash dump kernels is
499 0x1000000 (16MB). This can also be set based on the "X" value as
500 specified in the "crashkernel=YM@XM" command line boot parameter
501 passed to the panic-ed kernel. Typically this parameter is set as
502 crashkernel=64M@16M. Please take a look at
503 Documentation/kdump/kdump.txt for more details about crash dumps.
505 Don't change this unless you know what you are doing.
508 bool "Enable seccomp to safely compute untrusted bytecode"
512 This kernel feature is useful for number crunching applications
513 that may need to compute untrusted bytecode during their
514 execution. By using pipes or other transports made available to
515 the process as file descriptors supporting the read/write
516 syscalls, it's possible to isolate those applications in
517 their own address space using seccomp. Once seccomp is
518 enabled via /proc/<pid>/seccomp, it cannot be disabled
519 and the task is only allowed to execute a few safe syscalls
520 defined by each seccomp mode.
522 If unsure, say Y. Only embedded should say N here.
524 source kernel/Kconfig.hz
527 bool "Function reordering"
530 This option enables the toolchain to reorder functions for a more
531 optimal TLB usage. If you have pretty much any version of binutils,
532 this can increase your kernel build time by roughly one minute.
537 # Use the generic interrupt handling code in kernel/irq/:
539 config GENERIC_HARDIRQS
543 config GENERIC_IRQ_PROBE
547 # we have no ISA slots, but we do have ISA-style DMA.
552 config GENERIC_PENDING_IRQ
554 depends on GENERIC_HARDIRQS && SMP
557 menu "Power management options"
558 depends on !XEN_UNPRIVILEGED_GUEST
561 source kernel/power/Kconfig
564 source "drivers/acpi/Kconfig"
566 source "arch/x86_64/kernel/cpufreq/Kconfig"
570 menu "Bus options (PCI etc.)"
575 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
582 bool "Support mmconfig PCI config space access"
583 depends on PCI && ACPI
585 config XEN_PCIDEV_FRONTEND
586 bool "Xen PCI Frontend"
587 depends on PCI && X86_64_XEN
590 The PCI device frontend driver allows the kernel to import arbitrary
591 PCI devices from a PCI backend to support PCI driver domains.
593 config XEN_PCIDEV_FE_DEBUG
594 bool "Xen PCI Frontend Debugging"
595 depends on XEN_PCIDEV_FRONTEND
598 Enables some debug statements within the PCI Frontend.
600 source "drivers/pci/pcie/Kconfig"
602 source "drivers/pci/Kconfig"
604 source "drivers/pcmcia/Kconfig"
606 source "drivers/pci/hotplug/Kconfig"
611 menu "Executable file formats / Emulations"
613 source "fs/Kconfig.binfmt"
615 config IA32_EMULATION
616 bool "IA32 Emulation"
618 Include code to run 32-bit programs under a 64-bit kernel. You should likely
619 turn this on, unless you're 100% sure that you don't have any 32-bit programs
623 tristate "IA32 a.out support"
624 depends on IA32_EMULATION
626 Support old a.out binaries in the 32bit emulation.
630 depends on IA32_EMULATION
633 config SYSVIPC_COMPAT
635 depends on COMPAT && SYSVIPC
642 source drivers/Kconfig
644 source "drivers/firmware/Kconfig"
648 menu "Instrumentation Support"
649 depends on EXPERIMENTAL
651 source "arch/x86_64/oprofile/Kconfig"
654 bool "Kprobes (EXPERIMENTAL)"
655 depends on EXPERIMENTAL && MODULES
657 Kprobes allows you to trap at almost any kernel address and
658 execute a callback function. register_kprobe() establishes
659 a probepoint and specifies the callback. Kprobes is useful
660 for kernel debugging, non-intrusive instrumentation and testing.
661 If in doubt, say "N".
664 source "arch/x86_64/Kconfig.debug"
666 source "kernel/vserver/Kconfig"
668 source "security/Kconfig"
670 source "crypto/Kconfig"
672 source "drivers/xen/Kconfig"