Status
^^^^^^
*** UNSTABLE ***
The port is basically complete and many examples run correctly. However, there
are remaining instabilities that make the port un-usable. The nature of these
is not understood; the behavior is that certain SH-1 instructions stop working
as advertised. This could be a silicon problem, some pipeline issue that is not
handled properly by the gcc 3.4.5 toolchain (which has very limited SH-1 support
to begin with), or perhaps with the CMON debugger. At any rate, I have exhausted
all of the energy that I am willing to put into this cool old processor for the
time being.
Toolchain
^^^^^^^^^
A GNU GCC-based toolchain is assumed. The PATH environment variable should
be modified to point to the correct path to the SH toolchain (if
different from the default).
If you have no SH toolchain, one can be downloaded from the NuttX
Bitbucket download site (https://bitbucket.org/nuttx/buildroot/downloads/).
1. You must have already configured Nuttx in <some-dir>nuttx.
tools/configure.sh us7032evb1:<sub-dir>
2. Download the latest buildroot package into <some-dir>
3. unpack
4. cd <some-dir>/buildroot
5. cp boards/sh-defconfig .config
6. make oldconfig
7. make
8. Make sure that the PATH variable includes the path to the newly built
binaries.
shterm
^^^^^^
The USB7032EVB1 supports CMON in PROM. CMON requires special
serial interactions in order to upload and download program files.
Therefore, a standard terminal emulation program (such as minicom)
cannot be used.
The shterm subdirectory contains a small terminal emulation
program that supports these special interactions for file transfers.
Configurations
^^^^^^^^^^^^^^
Common Configuration Notes
--------------------------
1. Each SH-1 configuration is maintained in a sub-directory and
can be selected as follow:
tools/configure.sh us7032evb1:<subdir>
Where <subdir> is one of the configuration sub-directories described in
the following paragraph.
2. These configurations use the mconf-based configuration tool. To
change a configurations using that tool, you should:
a. Build and install the kconfig-mconf tool. See nuttx/README.txt
see additional README.txt files in the NuttX tools repository.
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
3. By default, all configurations assume that you are building under
Linux (should work under Windows with Cygwin as well). This is
is easily reconfigured:
CONFIG_HOST_LINUX=y
Configuration Sub-Directories
-----------------------------
ostest
This configuration directory, performs a simple OS test using
examples/ostest.
nsh
Configures the NuttShell (nsh) located at examples/nsh. The
Configuration enables only the serial NSH interfaces.
NOTE: At present, the NSH example does not run. See the "Status"
discussion above for a full explanation.
Configuration Options
^^^^^^^^^^^^^^^^^^^^^
In additional to the common configuration options listed in the
file boards/README.txt, there are other configuration options
specific to the SH-1
Architecture selection
CONFIG_ARCH - identifies the arch subdirectory and, hence, the
processor architecture. This should be renesas (for arch/renesas)
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory.
This should be sh1 (for arch/renesas/src/sh1 and arch/renesas/include/sh1)
CONFIG_ARCH_SH1 and CONFIG_ARCH_CHIP_SH7032 - for use in C code. These
identify the particular chip or SoC that the architecture is
implemented in.
CONFIG_ARCH_BOARD - identifies the boards/ subdirectory and, hence,
the board that supports the particular chip or SoC. This
should be us7032evb1 for (boards/us7032evb1).
CONFIG_ARCH_BOARD_US7032EVB1 - for use in C code
CONFIG_ENDIAN_BIG - the SH-1 usually runs big-endian
CONFIG_ARCH_NOINTC - define if the architecture does not
support an interrupt controller or otherwise cannot support
APIs like up_enable_irq() and up_disable_irq(). Should be
defined.
CONFIG_BOARD_LOOPSPERMSEC - for delay loops
CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to SH1_LCEVB1
CONFIG_RAM_SIZE - Describes the internal DRAM.
CONFIG_RAM_START - The start address of internal DRAM
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_SH1_DMAC0, CONFIG_SH1_DMAC1, CONFIG_SH1_DMAC2, CONFIG_SH1_DMAC3,
CONFIG_SH1_ITU1, CONFIG_SH1_ITU2, CONFIG_SH1_ITU3, CONFIG_SH1_ITU4,
CONFIG_SH1_SCI0, CONFIG_SH1_SCI1, CONFIG_SH1_PCU, CONFIG_SH1_AD,
CONFIG_SH1_WDT, CONFIG_SH1_CMI - Each unused chip block should b
disabled to save space
SH1 specific device driver settings
CONFIG_SCIn_SERIAL_CONSOLE - selects the SCIn for the
console and ttys0 (default is the UART0).
CONFIG_SCIn_RXBUFSIZE - Characters are buffered as received.
This specific the size of the receive buffer
CONFIG_SCIn_TXBUFSIZE - Characters are buffered before
being sent. This specific the size of the transmit buffer
CONFIG_SCIn_BAUD - The configure BAUD of the UART. Must be
CONFIG_SCIn_BITS - The number of bits. Must be either 7 or 8.
CONFIG_SCIn_PARTIY - 0=no parity, 1=odd parity, 2=even parity, 3=mark 1, 4=space 0
CONFIG_SCIn_2STOP - Two stop bits
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