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
157 depends on SMP && !MK8
160 config MATH_EMULATION
173 config X86_LOCAL_APIC
178 bool "MTRR (Memory Type Range Register) support"
180 On Intel P6 family processors (Pentium Pro, Pentium II and later)
181 the Memory Type Range Registers (MTRRs) may be used to control
182 processor access to memory ranges. This is most useful if you have
183 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
184 allows bus write transfers to be combined into a larger transfer
185 before bursting over the PCI/AGP bus. This can increase performance
186 of image write operations 2.5 times or more. Saying Y here creates a
187 /proc/mtrr file which may be used to manipulate your processor's
188 MTRRs. Typically the X server should use this.
190 This code has a reasonably generic interface so that similar
191 control registers on other processors can be easily supported
194 Saying Y here also fixes a problem with buggy SMP BIOSes which only
195 set the MTRRs for the boot CPU and not for the secondary CPUs. This
196 can lead to all sorts of problems, so it's good to say Y here.
198 Just say Y here, all x86-64 machines support MTRRs.
200 See <file:Documentation/mtrr.txt> for more information.
203 bool "Symmetric multi-processing support"
205 This enables support for systems with more than one CPU. If you have
206 a system with only one CPU, like most personal computers, say N. If
207 you have a system with more than one CPU, say Y.
209 If you say N here, the kernel will run on single and multiprocessor
210 machines, but will use only one CPU of a multiprocessor machine. If
211 you say Y here, the kernel will run on many, but not all,
212 singleprocessor machines. On a singleprocessor machine, the kernel
213 will run faster if you say N here.
215 If you don't know what to do here, say N.
218 bool "SMT (Hyperthreading) scheduler support"
222 SMT scheduler support improves the CPU scheduler's decision making
223 when dealing with Intel Pentium 4 chips with HyperThreading at a
224 cost of slightly increased overhead in some places. If unsure say
227 source "kernel/Kconfig.preempt"
230 bool "Non Uniform Memory Access (NUMA) Support"
233 Enable NUMA (Non Uniform Memory Access) support. The kernel
234 will try to allocate memory used by a CPU on the local memory
235 controller of the CPU and add some more NUMA awareness to the kernel.
236 This code is recommended on all multiprocessor Opteron systems.
237 If the system is EM64T, you should say N unless your system is EM64T
241 bool "Old style AMD Opteron NUMA detection"
245 Enable K8 NUMA node topology detection. You should say Y here if
246 you have a multi processor AMD K8 system. This uses an old
247 method to read the NUMA configurtion directly from the builtin
248 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
249 instead, which also takes priority if both are compiled in.
251 # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
253 config X86_64_ACPI_NUMA
254 bool "ACPI NUMA detection"
260 Enable ACPI SRAT based node topology detection.
263 bool "NUMA emulation"
266 Enable NUMA emulation. A flat machine will be split
267 into virtual nodes when booted with "numa=fake=N", where N is the
268 number of nodes. This is only useful for debugging.
270 config ARCH_DISCONTIGMEM_ENABLE
276 config ARCH_DISCONTIGMEM_ENABLE
280 config ARCH_DISCONTIGMEM_DEFAULT
284 config ARCH_SPARSEMEM_ENABLE
288 config ARCH_FLATMEM_ENABLE
294 config HAVE_ARCH_EARLY_PFN_TO_NID
298 int "Maximum number of CPUs (2-256)"
303 This allows you to specify the maximum number of CPUs which this
304 kernel will support. Current maximum is 256 CPUs due to
305 APIC addressing limits. Less depending on the hardware.
307 This is purely to save memory - each supported CPU requires
308 memory in the static kernel configuration.
311 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
312 depends on SMP && HOTPLUG && EXPERIMENTAL
314 Say Y here to experiment with turning CPUs off and on. CPUs
315 can be controlled through /sys/devices/system/cpu/cpu#.
316 Say N if you want to disable CPU hotplug.
323 Use the IA-PC HPET (High Precision Event Timer) to manage
324 time in preference to the PIT and RTC, if a HPET is
325 present. The HPET provides a stable time base on SMP
326 systems, unlike the TSC, but it is more expensive to access,
327 as it is off-chip. You can find the HPET spec at
328 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
335 Support the ACPI PM timer for time keeping. This is slow,
336 but is useful on some chipsets without HPET on systems with more
337 than one CPU. On a single processor or single socket multi core
338 system it is normally not required.
339 When the PM timer is active 64bit vsyscalls are disabled
340 and should not be enabled (/proc/sys/kernel/vsyscall64 should
342 The kernel selects the PM timer only as a last resort, so it is
343 useful to enable just in case.
345 config HPET_EMULATE_RTC
346 bool "Provide RTC interrupt"
347 depends on HPET_TIMER && RTC=y
354 Support the IOMMU. Needed to run systems with more than 3GB of memory
355 properly with 32-bit PCI devices that do not support DAC (Double Address
356 Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
357 Normally the kernel will take the right choice by itself.
358 This option includes a driver for the AMD Opteron/Athlon64 IOMMU
359 and a software emulation used on some other systems.
362 # need this always enabled with GART_IOMMU for the VIA workaround
365 depends on GART_IOMMU
370 depends on !GART_IOMMU && !SWIOTLB
373 Don't use IOMMU code. This will cause problems when you have more than 4GB
374 of memory and any 32-bit devices. Don't turn on unless you know what you
378 bool "Machine check support" if EMBEDDED
381 Include a machine check error handler to report hardware errors.
382 This version will require the mcelog utility to decode some
383 machine check error logs. See
384 ftp://ftp.x86-64.org/pub/linux/tools/mcelog
387 bool "Intel MCE features"
388 depends on X86_MCE && X86_LOCAL_APIC
391 Additional support for intel specific MCE features such as
395 bool "AMD MCE features"
396 depends on X86_MCE && X86_LOCAL_APIC
399 Additional support for AMD specific MCE features such as
400 the DRAM Error Threshold.
403 bool "kexec system call (EXPERIMENTAL)"
404 depends on EXPERIMENTAL
406 kexec is a system call that implements the ability to shutdown your
407 current kernel, and to start another kernel. It is like a reboot
408 but it is indepedent of the system firmware. And like a reboot
409 you can start any kernel with it, not just Linux.
411 The name comes from the similiarity to the exec system call.
413 It is an ongoing process to be certain the hardware in a machine
414 is properly shutdown, so do not be surprised if this code does not
415 initially work for you. It may help to enable device hotplugging
416 support. As of this writing the exact hardware interface is
417 strongly in flux, so no good recommendation can be made.
420 bool "kernel crash dumps (EXPERIMENTAL)"
421 depends on EXPERIMENTAL
423 Generate crash dump after being started by kexec.
425 config PHYSICAL_START
426 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
427 default "0x1000000" if CRASH_DUMP
430 This gives the physical address where the kernel is loaded. Normally
431 for regular kernels this value is 0x100000 (1MB). But in the case
432 of kexec on panic the fail safe kernel needs to run at a different
433 address than the panic-ed kernel. This option is used to set the load
434 address for kernels used to capture crash dump on being kexec'ed
435 after panic. The default value for crash dump kernels is
436 0x1000000 (16MB). This can also be set based on the "X" value as
437 specified in the "crashkernel=YM@XM" command line boot parameter
438 passed to the panic-ed kernel. Typically this parameter is set as
439 crashkernel=64M@16M. Please take a look at
440 Documentation/kdump/kdump.txt for more details about crash dumps.
442 Don't change this unless you know what you are doing.
445 bool "Enable seccomp to safely compute untrusted bytecode"
449 This kernel feature is useful for number crunching applications
450 that may need to compute untrusted bytecode during their
451 execution. By using pipes or other transports made available to
452 the process as file descriptors supporting the read/write
453 syscalls, it's possible to isolate those applications in
454 their own address space using seccomp. Once seccomp is
455 enabled via /proc/<pid>/seccomp, it cannot be disabled
456 and the task is only allowed to execute a few safe syscalls
457 defined by each seccomp mode.
459 If unsure, say Y. Only embedded should say N here.
461 source kernel/Kconfig.hz
466 # Use the generic interrupt handling code in kernel/irq/:
468 config GENERIC_HARDIRQS
472 config GENERIC_IRQ_PROBE
476 # we have no ISA slots, but we do have ISA-style DMA.
481 config GENERIC_PENDING_IRQ
483 depends on GENERIC_HARDIRQS && SMP
486 menu "Power management options"
488 source kernel/power/Kconfig
490 source "drivers/acpi/Kconfig"
492 source "arch/x86_64/kernel/cpufreq/Kconfig"
496 menu "Bus options (PCI etc.)"
501 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
508 bool "Support mmconfig PCI config space access"
509 depends on PCI && ACPI
512 bool "Unordered IO mapping access"
513 depends on EXPERIMENTAL
515 Use unordered stores to access IO memory mappings in device drivers.
516 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
517 work with this option, but it makes the drivers behave differently
518 from i386. Requires that the driver writer used memory barriers
521 source "drivers/pci/pcie/Kconfig"
523 source "drivers/pci/Kconfig"
525 source "drivers/pcmcia/Kconfig"
527 source "drivers/pci/hotplug/Kconfig"
532 menu "Executable file formats / Emulations"
534 source "fs/Kconfig.binfmt"
536 config IA32_EMULATION
537 bool "IA32 Emulation"
539 Include code to run 32-bit programs under a 64-bit kernel. You should likely
540 turn this on, unless you're 100% sure that you don't have any 32-bit programs
544 tristate "IA32 a.out support"
545 depends on IA32_EMULATION
547 Support old a.out binaries in the 32bit emulation.
551 depends on IA32_EMULATION
554 config SYSVIPC_COMPAT
556 depends on COMPAT && SYSVIPC
563 source drivers/Kconfig
565 source "drivers/firmware/Kconfig"
569 menu "Instrumentation Support"
570 depends on EXPERIMENTAL
572 source "arch/x86_64/oprofile/Kconfig"
575 bool "Kprobes (EXPERIMENTAL)"
577 Kprobes allows you to trap at almost any kernel address and
578 execute a callback function. register_kprobe() establishes
579 a probepoint and specifies the callback. Kprobes is useful
580 for kernel debugging, non-intrusive instrumentation and testing.
581 If in doubt, say "N".
584 source "arch/x86_64/Kconfig.debug"
586 source "security/Kconfig"
588 source "crypto/Kconfig"