# For a description of the syntax of this configuration file, # see Documentation/kbuild/config-language.txt. mainmenu "Linux/Xtensa Kernel Configuration" config FRAME_POINTER bool default n config XTENSA bool default y help Xtensa processors are 32-bit RISC machines designed by Tensilica primarily for embedded systems. These processors are both configurable and extensible. The Linux port to the Xtensa architecture supports all processor configurations and extensions, with reasonable minimum requirements. The Xtensa Linux project has a home page at <http://xtensa.sourceforge.net/>. config RWSEM_XCHGADD_ALGORITHM bool default y config GENERIC_FIND_NEXT_BIT bool default y config GENERIC_HWEIGHT bool default y config GENERIC_HARDIRQS bool default y source "init/Kconfig" menu "Processor type and features" choice prompt "Xtensa Processor Configuration" default XTENSA_CPU_LINUX_BE config XTENSA_CPU_LINUX_BE bool "linux_be" ---help--- The linux_be processor configuration is the baseline Xtensa configurations included in this kernel and also used by binutils, gcc, and gdb. It contains no TIE, no coprocessors, and the following configuration options: Code Density Option 2 Misc Special Registers NSA/NSAU Instructions 128-bit Data Bus Width Processor ID 8K, 2-way I and D Caches Zero-Overhead Loops 2 Inst Address Break Registers Big Endian 2 Data Address Break Registers 64 General-Purpose Registers JTAG Interface and Trace Port 17 Interrupts MMU w/ TLBs and Autorefill 3 Interrupt Levels 8 Autorefill Ways (I/D TLBs) 3 Timers Unaligned Exceptions endchoice config MMU bool default y config XTENSA_UNALIGNED_USER bool "Unaligned memory access in use space" ---help--- The Xtensa architecture currently does not handle unaligned memory accesses in hardware but through an exception handler. Per default, unaligned memory accesses are disabled in user space. Say Y here to enable unaligned memory access in user space. config PREEMPT bool "Preemptible Kernel" ---help--- This option reduces the latency of the kernel when reacting to real-time or interactive events by allowing a low priority process to be preempted even if it is in kernel mode executing a system call. Unfortunately the kernel code has some race conditions if both CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is currently disabled if you are building an SMP kernel. Say Y here if you are building a kernel for a desktop, embedded or real-time system. Say N if you are unsure. config MATH_EMULATION bool "Math emulation" help Can we use information of configuration file? config HIGHMEM bool "High memory support" endmenu menu "Platform options" choice prompt "Xtensa System Type" default XTENSA_PLATFORM_ISS config XTENSA_PLATFORM_ISS bool "ISS" help ISS is an acronym for Tensilica's Instruction Set Simulator. config XTENSA_PLATFORM_XT2000 bool "XT2000" help XT2000 is the name of Tensilica's feature-rich emulation platform. This hardware is capable of running a full Linux distribution. endchoice config XTENSA_CALIBRATE_CCOUNT bool "Auto calibration of the CPU clock rate" ---help--- On some platforms (XT2000, for example), the CPU clock rate can vary. The frequency can be determined, however, by measuring against a well known, fixed frequency, such as an UART oscillator. config XTENSA_CPU_CLOCK int "CPU clock rate [MHz]" depends on !XTENSA_CALIBRATE_CCOUNT default "16" config GENERIC_CALIBRATE_DELAY bool "Auto calibration of the BogoMIPS value" ---help--- The BogoMIPS value can easily be derived from the CPU frequency. config CMDLINE_BOOL bool "Default bootloader kernel arguments" config CMDLINE string "Initial kernel command string" depends on CMDLINE_BOOL default "console=ttyS0,38400 root=/dev/ram" help On some architectures (EBSA110 and CATS), there is currently no way for the boot loader to pass arguments to the kernel. For these architectures, you should supply some command-line options at build time by entering them here. As a minimum, you should specify the memory size and the root device (e.g., mem=64M root=/dev/nfs). config SERIAL_CONSOLE bool depends on XTENSA_PLATFORM_ISS default y config XTENSA_ISS_NETWORK bool depends on XTENSA_PLATFORM_ISS default y source "mm/Kconfig" endmenu menu "Bus options" config PCI bool "PCI support" if !XTENSA_PLATFORM_ISS depends on !XTENSA_PLATFORM_ISS default y help Find out whether you have a PCI motherboard. PCI is the name of a bus system, i.e. the way the CPU talks to the other stuff inside your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or VESA. If you have PCI, say Y, otherwise N. The PCI-HOWTO, available from <http://www.linuxdoc.org/docs.html#howto>, contains valuable information about which PCI hardware does work under Linux and which doesn't source "drivers/pci/Kconfig" config HOTPLUG bool "Support for hot-pluggable devices" ---help--- Say Y here if you want to plug devices into your computer while the system is running, and be able to use them quickly. In many cases, the devices can likewise be unplugged at any time too. One well known example of this is PCMCIA- or PC-cards, credit-card size devices such as network cards, modems or hard drives which are plugged into slots found on all modern laptop computers. Another example, used on modern desktops as well as laptops, is USB. Enable HOTPLUG and KMOD, and build a modular kernel. Get agent software (at <http://linux-hotplug.sourceforge.net/>) and install it. Then your kernel will automatically call out to a user mode "policy agent" (/sbin/hotplug) to load modules and set up software needed to use devices as you hotplug them. source "drivers/pcmcia/Kconfig" source "drivers/pci/hotplug/Kconfig" endmenu menu "Executable file formats" # only elf supported config KCORE_ELF bool depends on PROC_FS default y help If you enabled support for /proc file system then the file /proc/kcore will contain the kernel core image in ELF format. This can be used in gdb: $ cd /usr/src/linux ; gdb vmlinux /proc/kcore This is especially useful if you have compiled the kernel with the "-g" option to preserve debugging information. It is mainly used for examining kernel data structures on the live kernel. source "fs/Kconfig.binfmt" endmenu source "net/Kconfig" source "drivers/Kconfig" source "fs/Kconfig" menu "Xtensa initrd options" depends on BLK_DEV_INITRD config EMBEDDED_RAMDISK bool "Embed root filesystem ramdisk into the kernel" config EMBEDDED_RAMDISK_IMAGE string "Filename of gzipped ramdisk image" depends on EMBEDDED_RAMDISK default "ramdisk.gz" help This is the filename of the ramdisk image to be built into the kernel. Relative pathnames are relative to arch/xtensa/boot/ramdisk/. The ramdisk image is not part of the kernel distribution; you must provide one yourself. endmenu source "arch/xtensa/Kconfig.debug" source "security/Kconfig" source "crypto/Kconfig" source "lib/Kconfig"