README
^^^^^^
This README discusses issues unique to NuttX configurations for the
Freescale DEMO9S12NE64 development board.
Development Environment
^^^^^^^^^^^^^^^^^^^^^^^
Either Linux or Cygwin on Windows can be used for the development environment.
The source has been built only using the GNU toolchain (see below). Other
toolchains will likely cause problems.
NuttX buildroot Toolchain
^^^^^^^^^^^^^^^^^^^^^^^^^
A GNU GCC-based toolchain is assumed. The files */setenv.sh should
be modified to point to the correct path to the HC12 GCC toolchain (if
different from the default in your PATH variable).
If you have no HC12 toolchain, one can be downloaded from the NuttX
SourceForge download site (https://sourceforge.net/project/showfiles.php?group_id=189573).
This GNU toolchain builds and executes in the Linux or Cygwin
environments.
1. You must have already configured Nuttx in <some-dir>/nuttx.
cd tools
./configure.sh demo9s12nec64/<sub-dir>
2. Download the latest buildroot package into <some-dir>
3. unpack the buildroot tarball. The resulting directory may
have versioning information on it like buildroot-x.y.z. If so,
rename <some-dir>/buildroot-x.y.z to <some-dir>/buildroot.
4. cd <some-dir>/buildroot
5. cp configs/m68hc12-defconfig-3.4.6 .config
6. make oldconfig
7. make
8. Edit setenv.h, if necessary, so that the PATH variable includes
the path to the newly built binaries.
See the file configs/README.txt in the buildroot source tree. That has more
detailed PLUS some special instructions that you will need to follow if you are
building a Cortex-M3 toolchain for Cygwin under Windows.
HC12/DEMO9S12NEC64-specific Configuration Options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
CONFIG_ARCH - Identifies the arch/ subdirectory. This should
be set to:
CONFIG_ARCH=hc
CONFIG_ARCH_family - For use in C code:
CONFIG_ARCH_HC=y
CONFIG_ARCH_architecture - For use in C code:
CONFIG_ARCH_HC12=y
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP=mc92s12nec64
CONFIG_ARCH_CHIP_name - For use in C code
CONFIG_ARCH_CHIP_MCS92S12NEC64
CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=demo9s12nec64
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_DEMOS92S12NEC64 (for the Spectrum Digital C5471 EVM)
CONFIG_ARCH_LOOPSPERMSEC - Must be calibrated for correct operation
of delay loops
CONFIG_ENDIAN_BIG - define if big endian (default is little
endian)
CONFIG_DRAM_SIZE - Describes the installed RAM.
CONFIG_DRAM_START - The start address of installed RAM
CONFIG_DRAM_END - Should be (CONFIG_DRAM_START+CONFIG_DRAM_SIZE)
CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to boards that
have LEDs
CONFIG_ARCH_INTERRUPTSTACK - This architecture supports an interrupt
stack. If defined, this symbol is the size of the interrupt
stack in bytes. If not defined, the user task stacks will be
used during interrupt handling.
CONFIG_ARCH_STACKDUMP - Do stack dumps after assertions
CONFIG_ARCH_CALIBRATION - Enables some build in instrumentation that
cause a 100 second delay during boot-up. This 100 second delay
serves no purpose other than it allows you to calibratre
CONFIG_ARCH_LOOPSPERMSEC. You simply use a stop watch to measure
the 100 second delay then adjust CONFIG_ARCH_LOOPSPERMSEC until
the delay actually is 100 seconds.
HC12 specific chip initialization
HC12 specific device driver settings
CONFIG_UARTn_SERIAL_CONSOLE - selects the UARTn for the
console and ttys0 (default is the UART0).
CONFIG_UARTn_RXBUFSIZE - Characters are buffered as received.
This specific the size of the receive buffer
CONFIG_UARTn_TXBUFSIZE - Characters are buffered before
being sent. This specific the size of the transmit buffer
CONFIG_UARTn_BAUD - The configure BAUD of the UART.
CONFIG_UARTn_BITS - The number of bits. Must be either 7 or 8.
CONFIG_UARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity, 3=mark 1, 4=space 0
CONFIG_UARTn_2STOP - Two stop bits
Configurations
^^^^^^^^^^^^^^
Each Freescale HC12 configuration is maintained in a sudirectory and
can be selected as follow:
cd tools
./configure.sh demo9s12nec64/<subdir>
cd -
. ./setenv.sh
Where <subdir> is one of the following:
ostest:
This configuration directory, performs a simple OS test using
examples/ostest.
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