# # For a description of the syntax of this configuration file, # see Documentation/kbuild/kconfig-language.txt. # # Note: ISA is disabled and will hopefully never be enabled. # If you managed to buy an ISA x86-64 box you'll have to fix all the # ISA drivers you need yourself. # mainmenu "Linux Kernel Configuration" config X86_64 bool default y help Port to the x86-64 architecture. x86-64 is a 64-bit extension to the classical 32-bit x86 architecture. For details see . config 64BIT def_bool y config X86 bool default y config GENERIC_TIME bool default y config GENERIC_TIME_VSYSCALL bool default y config GENERIC_CMOS_UPDATE bool default y config CLOCKSOURCE_WATCHDOG bool default y config GENERIC_CLOCKEVENTS bool default y config GENERIC_CLOCKEVENTS_BROADCAST bool default y config ZONE_DMA32 bool default y config LOCKDEP_SUPPORT bool default y config STACKTRACE_SUPPORT bool default y config SEMAPHORE_SLEEPERS bool default y config MMU bool default y config ZONE_DMA bool default y config ISA bool config SBUS bool config GENERIC_HWEIGHT bool default y config GENERIC_ISA_DMA bool default y config GENERIC_IOMAP bool default y config ARCH_MAY_HAVE_PC_FDC bool default y config ARCH_POPULATES_NODE_MAP def_bool y config DMI bool default y config AUDIT_ARCH bool default y config GENERIC_BUG bool default y depends on BUG source "init/Kconfig" menu "Processor type and features" source "kernel/time/Kconfig" choice prompt "Subarchitecture Type" default X86_PC config X86_PC bool "PC-compatible" help Choose this option if your computer is a standard PC or compatible. config X86_VSMP bool "Support for ScaleMP vSMP" depends on PCI help Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is supposed to run on these EM64T-based machines. Only choose this option if you have one of these machines. endchoice source "arch/x86/Kconfig.cpu" config MICROCODE tristate "/dev/cpu/microcode - Intel CPU microcode support" select FW_LOADER ---help--- If you say Y here the 'File systems' section, you will be able to update the microcode on Intel processors. You will obviously need the actual microcode binary data itself which is not shipped with the Linux kernel. For latest news and information on obtaining all the required ingredients for this driver, check: . To compile this driver as a module, choose M here: the module will be called microcode. If you use modprobe or kmod you may also want to add the line 'alias char-major-10-184 microcode' to your /etc/modules.conf file. config MICROCODE_OLD_INTERFACE bool depends on MICROCODE default y config X86_MSR tristate "/dev/cpu/*/msr - Model-specific register support" help This device gives privileged processes access to the x86 Model-Specific Registers (MSRs). It is a character device with major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. MSR accesses are directed to a specific CPU on multi-processor systems. config X86_CPUID tristate "/dev/cpu/*/cpuid - CPU information support" help This device gives processes access to the x86 CPUID instruction to be executed on a specific processor. It is a character device with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to /dev/cpu/31/cpuid. config X86_HT bool depends on SMP && !MK8 default y config MATH_EMULATION bool config MCA bool config EISA bool config X86_IO_APIC bool default y config X86_LOCAL_APIC bool default y config MTRR bool "MTRR (Memory Type Range Register) support" ---help--- On Intel P6 family processors (Pentium Pro, Pentium II and later) the Memory Type Range Registers (MTRRs) may be used to control processor access to memory ranges. This is most useful if you have a video (VGA) card on a PCI or AGP bus. Enabling write-combining allows bus write transfers to be combined into a larger transfer before bursting over the PCI/AGP bus. This can increase performance of image write operations 2.5 times or more. Saying Y here creates a /proc/mtrr file which may be used to manipulate your processor's MTRRs. Typically the X server should use this. This code has a reasonably generic interface so that similar control registers on other processors can be easily supported as well. Saying Y here also fixes a problem with buggy SMP BIOSes which only set the MTRRs for the boot CPU and not for the secondary CPUs. This can lead to all sorts of problems, so it's good to say Y here. Just say Y here, all x86-64 machines support MTRRs. See for more information. config SMP bool "Symmetric multi-processing support" ---help--- This enables support for systems with more than one CPU. If you have a system with only one CPU, like most personal computers, say N. If you have a system with more than one CPU, say Y. If you say N here, the kernel will run on single and multiprocessor machines, but will use only one CPU of a multiprocessor machine. If you say Y here, the kernel will run on many, but not all, singleprocessor machines. On a singleprocessor machine, the kernel will run faster if you say N here. If you don't know what to do here, say N. config SCHED_SMT bool "SMT (Hyperthreading) scheduler support" depends on SMP default n help SMT scheduler support improves the CPU scheduler's decision making when dealing with Intel Pentium 4 chips with HyperThreading at a cost of slightly increased overhead in some places. If unsure say N here. config SCHED_MC bool "Multi-core scheduler support" depends on SMP default y help Multi-core scheduler support improves the CPU scheduler's decision making when dealing with multi-core CPU chips at a cost of slightly increased overhead in some places. If unsure say N here. source "kernel/Kconfig.preempt" config NUMA bool "Non Uniform Memory Access (NUMA) Support" depends on SMP help Enable NUMA (Non Uniform Memory Access) support. The kernel will try to allocate memory used by a CPU on the local memory controller of the CPU and add some more NUMA awareness to the kernel. This code is recommended on all multiprocessor Opteron systems. If the system is EM64T, you should say N unless your system is EM64T NUMA. config K8_NUMA bool "Old style AMD Opteron NUMA detection" depends on NUMA && PCI default y help Enable K8 NUMA node topology detection. You should say Y here if you have a multi processor AMD K8 system. This uses an old method to read the NUMA configuration directly from the builtin Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, which also takes priority if both are compiled in. config NODES_SHIFT int default "6" depends on NEED_MULTIPLE_NODES # Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig. config X86_64_ACPI_NUMA bool "ACPI NUMA detection" depends on NUMA select ACPI select PCI select ACPI_NUMA default y help Enable ACPI SRAT based node topology detection. config NUMA_EMU bool "NUMA emulation" depends on NUMA help Enable NUMA emulation. A flat machine will be split into virtual nodes when booted with "numa=fake=N", where N is the number of nodes. This is only useful for debugging. config ARCH_DISCONTIGMEM_ENABLE bool depends on NUMA default y config ARCH_DISCONTIGMEM_DEFAULT def_bool y depends on NUMA config ARCH_SPARSEMEM_ENABLE def_bool y depends on (NUMA || EXPERIMENTAL) select SPARSEMEM_VMEMMAP_ENABLE config ARCH_MEMORY_PROBE def_bool y depends on MEMORY_HOTPLUG config ARCH_FLATMEM_ENABLE def_bool y depends on !NUMA source "mm/Kconfig" config MEMORY_HOTPLUG_RESERVE def_bool y depends on (MEMORY_HOTPLUG && DISCONTIGMEM) config HAVE_ARCH_EARLY_PFN_TO_NID def_bool y depends on NUMA config OUT_OF_LINE_PFN_TO_PAGE def_bool y depends on DISCONTIGMEM config NR_CPUS int "Maximum number of CPUs (2-255)" range 2 255 depends on SMP default "8" help This allows you to specify the maximum number of CPUs which this kernel will support. Current maximum is 255 CPUs due to APIC addressing limits. Less depending on the hardware. This is purely to save memory - each supported CPU requires memory in the static kernel configuration. config PHYSICAL_ALIGN hex default "0x200000" config HOTPLUG_CPU bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)" depends on SMP && HOTPLUG && EXPERIMENTAL help Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu/cpu#. This is also required for suspend/hibernation on SMP systems. Say N if you want to disable CPU hotplug and don't need to suspend. config ARCH_ENABLE_MEMORY_HOTPLUG def_bool y config HPET_TIMER bool default y help Use the IA-PC HPET (High Precision Event Timer) to manage time in preference to the PIT and RTC, if a HPET is present. The HPET provides a stable time base on SMP systems, unlike the TSC, but it is more expensive to access, as it is off-chip. You can find the HPET spec at . config HPET_EMULATE_RTC bool depends on HPET_TIMER && RTC=y default y # Mark as embedded because too many people got it wrong. # The code disables itself when not needed. config GART_IOMMU bool "GART IOMMU support" if EMBEDDED default y select SWIOTLB select AGP depends on PCI help Support for full DMA access of devices with 32bit memory access only on systems with more than 3GB. This is usually needed for USB, sound, many IDE/SATA chipsets and some other devices. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART based hardware IOMMU and a software bounce buffer based IOMMU used on Intel systems and as fallback. The code is only active when needed (enough memory and limited device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified too. config CALGARY_IOMMU bool "IBM Calgary IOMMU support" select SWIOTLB depends on PCI && EXPERIMENTAL help Support for hardware IOMMUs in IBM's xSeries x366 and x460 systems. Needed to run systems with more than 3GB of memory properly with 32-bit PCI devices that do not support DAC (Double Address Cycle). Calgary also supports bus level isolation, where all DMAs pass through the IOMMU. This prevents them from going anywhere except their intended destination. This catches hard-to-find kernel bugs and mis-behaving drivers and devices that do not use the DMA-API properly to set up their DMA buffers. The IOMMU can be turned off at boot time with the iommu=off parameter. Normally the kernel will make the right choice by itself. If unsure, say Y. config CALGARY_IOMMU_ENABLED_BY_DEFAULT bool "Should Calgary be enabled by default?" default y depends on CALGARY_IOMMU help Should Calgary be enabled by default? if you choose 'y', Calgary will be used (if it exists). If you choose 'n', Calgary will not be used even if it exists. If you choose 'n' and would like to use Calgary anyway, pass 'iommu=calgary' on the kernel command line. If unsure, say Y. # need this always selected by IOMMU for the VIA workaround config SWIOTLB bool help Support for software bounce buffers used on x86-64 systems which don't have a hardware IOMMU (e.g. the current generation of Intel's x86-64 CPUs). Using this PCI devices which can only access 32-bits of memory can be used on systems with more than 3 GB of memory. If unsure, say Y. config X86_MCE bool "Machine check support" if EMBEDDED default y help Include a machine check error handler to report hardware errors. This version will require the mcelog utility to decode some machine check error logs. See ftp://ftp.x86-64.org/pub/linux/tools/mcelog config X86_MCE_INTEL bool "Intel MCE features" depends on X86_MCE && X86_LOCAL_APIC default y help Additional support for intel specific MCE features such as the thermal monitor. config X86_MCE_AMD bool "AMD MCE features" depends on X86_MCE && X86_LOCAL_APIC default y help Additional support for AMD specific MCE features such as the DRAM Error Threshold. config KEXEC bool "kexec system call" help kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot but it is independent of the system firmware. And like a reboot you can start any kernel with it, not just Linux. The name comes from the similarity to the exec system call. It is an ongoing process to be certain the hardware in a machine is properly shutdown, so do not be surprised if this code does not initially work for you. It may help to enable device hotplugging support. As of this writing the exact hardware interface is strongly in flux, so no good recommendation can be made. config CRASH_DUMP bool "kernel crash dumps (EXPERIMENTAL)" depends on EXPERIMENTAL help Generate crash dump after being started by kexec. This should be normally only set in special crash dump kernels which are loaded in the main kernel with kexec-tools into a specially reserved region and then later executed after a crash by kdump/kexec. The crash dump kernel must be compiled to a memory address not used by the main kernel or BIOS using PHYSICAL_START, or it must be built as a relocatable image (CONFIG_RELOCATABLE=y). For more details see Documentation/kdump/kdump.txt config RELOCATABLE bool "Build a relocatable kernel (EXPERIMENTAL)" depends on EXPERIMENTAL help Builds a relocatable kernel. This enables loading and running a kernel binary from a different physical address than it has been compiled for. One use is for the kexec on panic case where the recovery kernel must live at a different physical address than the primary kernel. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address it has been loaded at and the compile time physical address (CONFIG_PHYSICAL_START) is ignored. config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) default "0x200000" help This gives the physical address where the kernel is loaded. It should be aligned to 2MB boundary. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then bzImage will decompress itself to above physical address and run from there. Otherwise, bzImage will run from the address where it has been loaded by the boot loader and will ignore above physical address. In normal kdump cases one does not have to set/change this option as now bzImage can be compiled as a completely relocatable image (CONFIG_RELOCATABLE=y) and be used to load and run from a different address. This option is mainly useful for the folks who don't want to use a bzImage for capturing the crash dump and want to use a vmlinux instead. So if you are using bzImage for capturing the crash dump, leave the value here unchanged to 0x200000 and set CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux for capturing the crash dump change this value to start of the reserved region (Typically 16MB 0x1000000). In other words, it can be set based on the "X" value as specified in the "crashkernel=YM@XM" command line boot parameter passed to the panic-ed kernel. Typically this parameter is set as crashkernel=64M@16M. Please take a look at Documentation/kdump/kdump.txt for more details about crash dumps. Usage of bzImage for capturing the crash dump is advantageous as one does not have to build two kernels. Same kernel can be used as production kernel and capture kernel. Don't change this unless you know what you are doing. config SECCOMP bool "Enable seccomp to safely compute untrusted bytecode" depends on PROC_FS default y help This kernel feature is useful for number crunching applications that may need to compute untrusted bytecode during their execution. By using pipes or other transports made available to the process as file descriptors supporting the read/write syscalls, it's possible to isolate those applications in their own address space using seccomp. Once seccomp is enabled via /proc//seccomp, it cannot be disabled and the task is only allowed to execute a few safe syscalls defined by each seccomp mode. If unsure, say Y. Only embedded should say N here. config CC_STACKPROTECTOR bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" depends on EXPERIMENTAL help This option turns on the -fstack-protector GCC feature. This feature puts, at the beginning of critical functions, a canary value on the stack just before the return address, and validates the value just before actually returning. Stack based buffer overflows (that need to overwrite this return address) now also overwrite the canary, which gets detected and the attack is then neutralized via a kernel panic. This feature requires gcc version 4.2 or above, or a distribution gcc with the feature backported. Older versions are automatically detected and for those versions, this configuration option is ignored. config CC_STACKPROTECTOR_ALL bool "Use stack-protector for all functions" depends on CC_STACKPROTECTOR help Normally, GCC only inserts the canary value protection for functions that use large-ish on-stack buffers. By enabling this option, GCC will be asked to do this for ALL functions. source kernel/Kconfig.hz config K8_NB def_bool y depends on AGP_AMD64 || GART_IOMMU || (PCI && NUMA) endmenu # # Use the generic interrupt handling code in kernel/irq/: # config GENERIC_HARDIRQS bool default y config GENERIC_IRQ_PROBE bool default y config GENERIC_PENDING_IRQ bool depends on GENERIC_HARDIRQS && SMP default y source "arch/x86/Kconfig"