# 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"
