Board-Specific Configurations
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Table of Contents
^^^^^^^^^^^^^^^^^
o Board-Specific Configurations
o Summary of Files
o Supported Architectures
o Configuring NuttX
Board-Specific Configurations
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The NuttX configuration consists of:
o Processor architecture specific files. These are the files contained
in the arch/<arch-name>/ directory.
o Chip/SoC specific files. Each processor processor architecture
is embedded in chip or System-on-a-Chip (SoC) architecture. The
full chip architecture includes the processor architecture plus
chip-specific interrupt logic, general purpose I/O (GIO) logic, and
specialized, internal peripherals (such as UARTs, USB, etc.).
These chip-specific files are contained within chip-specific
sub-directories in the arch/<arch-name>/ directory and are selected
via the CONFIG_ARCH_name selection
o Board specific files. In order to be usable, the chip must be
contained in a board environment. The board configuration defines
additional properties of the board including such things as
peripheral LEDs, external peripherals (such as network, USB, etc.).
These board-specific configuration files can be found in the
configs/<board-name>/ sub-directories and are discussed in this
README.
The configs/ subdirectory contains configuration data for each board. These
board-specific configurations plus the architecture-specific configurations in
the arch/ subdirectory completely define a customized port of NuttX.
Directory Structure
^^^^^^^^^^^^^^^^^^^
The configs directory contains board specific configurationlogic. Each
board must provide a subdirectory <board-name> under configs/ with the
following characteristics:
<board-name>
|-- include/
| `-- (board-specific header files)
|-- src/
| |-- Makefile
| `-- (board-specific source files)
|-- Make.defs
|-- defconfig
`-- setenv.sh
Summary of Files
^^^^^^^^^^^^^^^^
include/ -- This directory contains board specific header files. This
directory will be linked as include/arch/board at configuration time and
can be included via '#include <arch/board/header.h>'. These header file
can only be included by files in arch/<arch-name>include/ and
arch/<arch-name>/src
src/ -- This directory contains board specific drivers. This
directory will be linked as arch/<arch-name>/src/board at configuration
time and will be integrated into the build system.
src/Makefile -- This makefile will be invoked to build the board specific
drivers. It must support the following targets: libext$(LIBEXT), clean,
and distclean.
Make.defs -- This makefile fragment provides architecture and
tool-specific build options. It will be included by all other
makefiles in the build (once it is installed). This make fragment
should define:
Tools: CC, LD, AR, NM, OBJCOPY, OBJDUMP
Tool options: CFLAGS, LDFLAGS
When this makefile fragment runs, it will be passed TOPDIR which
is the path to the root directory of the build. This makefile
fragment may include ${TOPDIR}/.config to perform configuration
specific settings. For example, the CFLAGS will most likely be
different if CONFIG_DEBUG=y.
defconfig -- This is a configuration file similar to the Linux
configuration file. In contains varialble/value pairs like:
CONFIG_VARIABLE=value
This configuration file will be used at build time:
(1) as a makefile fragment included in other makefiles, and
(2) to generate include/nuttx/config.h which is included by
most C files in the system.
The following variables are recognized by the build (you may
also include architecture/board-specific settings).
Architecture selection:
CONFIG_ARCH - Identifies the arch/ subdirectory
CONFIG_ARCH_name - For use in C code
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP_name - For use in C code
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ENDIAN_BIG - define if big endian (default is little
endian)
Some architectures require a description of the the RAM configuration:
CONFIG_DRAM_SIZE - Describes the installed DRAM.
CONFIG_DRAM_START - The start address of DRAM (physical)
CONFIG_DRAM_VSTART - The startaddress of DRAM (virtual)
General OS setup
CONFIG_EXAMPLE - identifies the subdirectory in examples
that will be used in the build
CONFIG_DEBUG - enables built-in debug options
CONFIG_DEBUG_VERBOSE - enables verbose debug output
CONFIG_HAVE_LOWPUTC - architecture supports low-level, boot
time console output
CONFIG_MM_REGIONS - If the architecture includes multiple
regions of memory to allocate from, this specifies the
number of memory regions that the memory manager must
handle and enables the API mm_addregion(start, end);
CONFIG_TICKS_PER_MSEC - The default system timer is 100Hz
or TICKS_PER_MSEC=10. This setting may be defined to
inform NuttX that the processor hardware is providing
system timer interrupts at some interrupt interval other
than 10 msec.
CONFIG_RR_INTERVAL - The round robin timeslice will be set
this number of milliseconds; Round robin scheduling can
be disabled by setting this value to zero.
CONFIG_SCHED_INSTRUMENTATION - enables instrumentation in
scheduler to monitor system performance
CONFIG_TASK_NAME_SIZE - Spcifies that maximum size of a
task name to save in the TCB. Useful if scheduler
instrumentation is selected. Set to zero to disable.
CONFIG_START_YEAR, CONFIG_START_MONTH, CONFIG_START_DAY -
Used to initialize the internal time logic.
CONFIG_JULIAN_TIME - Enables Julian time conversions
CONFIG_DEV_CONSOLE - Set if architecture-specific logic
provides /dev/console. Enables stdout, stderr, stdin.
The following can be used to disable categories of APIs supported
by the OS. If the compiler supports weak functions, then it
should not be necessary to disable functions unless you want to
restrict usage of those APIs.
There are certain dependency relationships in these features.
o mq_notify logic depends on signals to awaken tasks
waiting for queues to become full or empty.
o pthread_condtimedwait() depends on signals to wake
up waiting tasks.
CONFIG_DISABLE_CLOCK, CONFIG_DISABLE_POSIX_TIMERS, CONFIG_DISABLE_PTHREAD.
CONFIG_DISABLE_SIGNALS, CONFIG_DISABLE_MQUEUE, CONFIG_DISABLE_MOUNTPOUNT
Misc libc settings
CONFIG_NOPRINTF_FIELDWIDTH - sprintf-related logic is a
little smaller if we do not support fieldwidthes
Allow for architecture optimized implementations
The architecture can provide optimized versions of the
following to improve sysem performance
CONFIG_ARCH_MEMCPY, CONFIG_ARCH_MEMCMP, CONFIG_ARCH_MEMMOVE
CONFIG_ARCH_MEMSET, CONFIG_ARCH_STRCMP, CONFIG_ARCH_STRCPY
CONFIG_ARCH_STRNCPY, CONFIG_ARCH_STRLEN, CONFIG_ARCH_BZERO
CONFIG_ARCH_KMALLOC, CONFIG_ARCH_KZMALLOC, CONFIG_ARCH_KFREE
Sizes of configurable things (0 disables)
CONFIG_MAX_TASKS - The maximum number of simultaneously
active tasks. This value must be a power of two.
CONFIG_NPTHREAD_KEYS - The number of items of thread-
specific data that can be retained
CONFIG_NFILE_DESCRIPTORS - The maximum number of file
descriptors (one for each open)
CONFIG_NFILE_STREAMS - The maximum number of streams that
can be fopen'ed
CONFIG_NAME_MAX - The maximum size of a file name.
CONFIG_STDIO_BUFFER_SIZE - Size of the buffer to allocate
on fopen. (Only if CONFIG_NFILE_STREAMS > 0)
CONFIG_NUNGET_CHARS - Number of characters that can be
buffered by ungetc() (Only if CONFIG_NFILE_STREAMS > 0)
CONFIG_PREALLOC_MQ_MSGS - The number of pre-allocated message
structures. The system manages a pool of preallocated
message structures to minimize dynamic allocations
CONFIG_MQ_MAXMSGSIZE - Message structures are allocated with
a fixed payload size given by this settin (does not include
other message structure overhead.
CONFIG_PREALLOC_WDOGS - The number of pre-allocated watchdog
structures. The system manages a pool of preallocated
watchdog structures to minimize dynamic allocations
Stack and heap information
CONFIG_BOOT_FROM_FLASH - Some configurations support XIP
operation from FLASH.
CONFIG_STACK_POINTER - The initial stack pointer
CONFIG_PROC_STACK_SIZE - The size of the initial stack
CONFIG_PTHREAD_STACK_MIN - Minimum pthread stack size
CONFIG_PTHREAD_STACK_DEFAULT - Default pthread stack size
CONFIG_HEAP_BASE - The beginning of the heap
CONFIG_HEAP_SIZE - The size of the heap
setenv.sh -- This is a script that you can include that will be installed at
the toplevel of the directory structure and can be sourced to set any
necessary environment variables.
Supported Boards
^^^^^^^^^^^^^^^^
configs/sim
A user-mode port of NuttX to the x86 Linux platform is available.
The purpose of this port is primarily to support OS feature developement.
This port does not support interrupts or a real timer (and hence no
round robin scheduler) Otherwise, it is complete.
configs/c5471evm
This is a port to the Spectrum Digital C5471 evaluation board. The
C5471 is a dual core processor from TI with an ARM7TDMI general purpose
processor and a c54 SDP. NuttX runs on the ARM core and is built with
with a GNU arm-elf toolchain*. This port is complete, verified, and
included in the NuttX release.
configs/mcu123-lpc214x
This is a port to the mcu123.com lpc214x development board.
This OS is also built with the the arm-elf toolchain*
configs/ntosd-dm320
This port uses the Neuros OSD with a GNU arm-elf toolchain*:
see http://wiki.neurostechnology.com/index.php/Developer_Welcome .
NuttX operates on the ARM9EJS of this dual core processor.
STATUS: This port is code complete, verified, and included in the
NuttX 0.2.1 release.
configs/mcu123-lpc214x
This port is for the NXP LPC2148 as provided on the mcu123.com
lpc214x development board.
STATUS: This port is in progress and should be available in the
nuttx-0.2.5 release.
configs/m68322evb
This is a work in progress for the venerable m68322evb board from
Motorola. This OS is also built with the the arm-elf toolchain*.
configs/pjrc-8051
8051 Microcontroller. This port uses the PJRC 87C52 development system
and the SDCC toolchain. This port is not quite ready for prime time.
Other ports for the for the TI TMS320DM270, M683222 and for MIPS are in various
states of progress
Configuring NuttX
^^^^^^^^^^^^^^^^^
Configuring NuttX requires only copying
configs/<board-name>/Make.def to ${TOPDIR}/Make.defs
configs/<board-name>/setenv.sh to ${TOPDIR}/setenv.sh
configs/<board-name>/defconfig to ${TOPDIR}/.config
There is a script that automates these steps. The following steps will
accomplish the same configuration:
cd tools
./configure.sh <board-name>
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