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README
^^^^^^
This README discusses issues unique to NuttX configurations for the
MCU-123 LPC2148 development board.
Contents
--------
o Development Environment
o GNU Toolchain Options
o NuttX buildroot Toolchain
o Flash Tools
- In System Programming (ISP) Mode
- LPC21ISP (Linux)
- FlashMagic (Windows/MAC)
- OpenOCD
o ARM/LPC214X-specific Configuration Options
o Configurations
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.
GNU Toolchain Options
^^^^^^^^^^^^^^^^^^^^^
The NuttX make system has been modified to support the following different
toolchain options.
1. The NuttX buildroot Toolchain (see below), or
2. The GNU EABI toolchain,
All testing has been conducted using the NuttX buildroot toolchain. To use
the CodeSourcery or devkitARM GNU toolchain, you simply need to build the
system as follows:
make # Will build for the NuttX buildroot toolchain
make CROSSDEV=arm-eabi- # Will build for the devkitARM toolchain
make CROSSDEV=arm-none-eabi- # Will build for the ARM EABI toolchain
make CROSSDEV=arm-nuttx-elf- # Will build for the NuttX buildroot toolchain
Of course, hard coding this CROSS_COMPILE value in Make.defs file will save
some repetitive typing.
NuttX buildroot Toolchain
^^^^^^^^^^^^^^^^^^^^^^^^^
A GNU GCC-based toolchain is assumed. The PATH environment variable should
be modified to point to the correct path to the Cortex-M3 GCC toolchain (if
different from the default in your PATH variable).
If you have no Cortex-M3 toolchain, one can be downloaded from the NuttX
Bitbucket download site (https://bitbucket.org/nuttx/buildroot/downloads/).
This GNU toolchain builds and executes in the Linux or Cygwin environment.
1. You must have already configured NuttX in <some-dir>/nuttx.
tools/configure.sh eagle100:<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 boards/arm7tdmi-defconfig-4.3.3 .config
6. make oldconfig
7. make
8. Make sure that the PATH variable includes the path to the newly built
binaries.
See the file boards/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.
Flash Tools
^^^^^^^^^^^
In System Programming (ISP) Mode
--------------------------------
1. Make sure you exit minicom (or whatever terminal emulator you are
using). It will interfere with the download.
2. On the MCU123 board, I need to put a jumper on JP3-INT. On that board,
JP3-INT is connected to P0.14 of LPC214x. When P0.14 is low and RTS is
changed from high to low, the LPC214x will enter ISP (In System
Programming) state.
J2-RST: When J2 is shorted, the reset pin of CPU is controlled by
the DTR signal of UART0. Short J2 to enable ISP automatic download.
Alternatively, you can just press the INT1 button while resetting.
The LEDs will be off if the LPC2148 successfully enters ISP mode.
Resetting the board will enter ISP mode when the jumper is connected.
LPC21ISP (Linux)
----------------
(ca. 2008)
I use the lpc21isp tool to load NuttX into FLASH. In the older version
1.60 of lpc21isp for Linux, I had to make several changes. This changesi
are shown in lpc21ips-1.60.diff.
I use the script lpc21isp.sh to perform the actual download. You will
probably have to make some changes to this script in order to use it.
For example, the path to the built lpc21isp binary will most likely
have to change. Then move this script to the top level NuttX
directory and simply execute it to load NuttX onto the board (after
entering ISP mode).
Here are the detailed steps I use:
1. Setup ISP (In System Programming) mode (see above).
3. Start lpc21isp.sh
4. Reset the board to
FlashMagic (Windows/MAC)
------------------------
(ca. 2012)
You download FlashMagic for Windows or MAC here: http://www.flashmagictool.com
1. Setup ISP (In System Programming) mode (see above).
2. Start FlashMagic and setup communication parameters.
Device: LPC2148
COM Port: (will vary with PC)
Baud: 38400 (I am sure it can go faster).
Interface: None (ISP)
Oscillator (MHz): 12
Check "Erase all Flash+Code Rd Prot"
3. Select the nuttx.hex file
4. Options: Verify after programming
5. Start and reset the board to entry ISP mode. Or hold the INT1
button down after reset after you press start.
NOTE: FlashMagic will complain if the data section overlaps
0x4000000-0x400001ff.
OpenOCD
-------
I have the (really old) Olimex software installed at C:/gccfd. Under
Cygwin, I can do the following:
1. Create a .cfg file:
$ cat /cygdrive/c/gccfd/openocd/lib/openocd/interface/arm-usb-ocd.cfg /cygdrive/c/gccfd/openocd/lib/openocd/target/lpc2148.cfg > lpc2148.cfg
2. Start OpenOCD:
/cygdrive/c/gccfd/openocd/bin/openocd-ftd2xx.exe -f lpc2148.cfg -s . &
3. Start arm-*-gdb (whichever GDB your toolchain uses).
ARM/LPC214X-specific Configuration Options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
CONFIG_ARCH - Identifies the arch/ subdirectory. This should
be set to:
CONFIG_ARCH=arm
CONFIG_ARCH_family - For use in C code:
CONFIG_ARCH_ARM=y
CONFIG_ARCH_architecture - For use in C code:
CONFIG_ARCH_ARM7TDMI=y
CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
CONFIG_ARCH_CHIP=lpc214x
CONFIG_ARCH_CHIP_name - For use in C code
CONFIG_ARCH_CHIP_LPC214X
CONFIG_ARCH_BOARD - Identifies the boards/ subdirectory and
hence, the board that supports the particular chip or SoC.
CONFIG_ARCH_BOARD=mcu123-lpc214x
CONFIG_ARCH_BOARD_name - For use in C code
CONFIG_ARCH_BOARD_MCU123_LPC214X (for theMCU123 LPC214x board)
CONFIG_ARCH_LOOPSPERMSEC - Must be calibrated for correct operation
of delay loops
CONFIG_ENDIAN_BIG - define if big endian (default is little
endian)
CONFIG_RAM_SIZE - Describes the installed RAM.
CONFIG_RAM_START - The start address of installed RAM
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
LPC2148 specific chip initialization
These provide register setup values:
CONFIG_EXTMEM_MODE, CONFIG_RAM_MODE, CONFIG_CODE_BASE, CONFIG_PLL_SETUP,
CONFIG_MAM_SETUP, CONFIG_APBDIV_SETUP, CONFIG_EMC_SETUP, CONFIG_BCFG0_SETUP,
CONFIG_BCFG1_SETUP, CONFIG_BCFG2_SETUP, CONFIG_BCFG3_SETUP, CONFIG_ADC_SETUP
CONFIG_LPC214x_FIO - Enable fast GPIO (vs. legacy, "old" GPIO).
LPC214X 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
LPC214X USB Configuration
CONFIG_LPC214X_USBDEV_FRAME_INTERRUPT
Handle USB Start-Of-Frame events.
Enable reading SOF from interrupt handler vs. simply reading on demand.
Probably a bad idea... Unless there is some issue with sampling the SOF
from hardware asynchronously.
CONFIG_LPC214X_USBDEV_EPFAST_INTERRUPT
Enable high priority interrupts. I have no idea why you might want to
do that
CONFIG_LPC214X_USBDEV_NDMADESCRIPTORS
Number of DMA descriptors to allocate in the 8Kb USB RAM. This is a
tradeoff between the number of DMA channels that can be supported vs
the size of the DMA buffers available.
CONFIG_LPC214X_USBDEV_DMA
Enable lpc214x-specific DMA support
Configurations
^^^^^^^^^^^^^^
1. Each NXP LPC214x configuration is maintained in a sub-directory and
can be selected as follow:
tools/configure.sh mcu123-lpc214x:<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 the NuttX Buildroot toolchain
under Linux (should work under Windows with Cygwin as well). This
is easily reconfigured:
CONFIG_HOST_LINUX=y
CONFIG_ARM_TOOLCHAIN_BUILDROOT=y
composite:
----------
A simple test of the USB Composite Device (see
apps/examples/README.txt and apps/system/composite)
NOTE: I could not get this to work! Perhaps this is a consequence of the
last USB driver checking (r4359). But backing this change out did not fix
the configuration.
nsh:
----
Configures the NuttShell (nsh) located at examples/nsh. The
Configuration enables only the serial NSH interfaces.
usbserial:
----------
This configuration directory exercises the USB serial class
driver at examples/usbserial. See examples/README.txt for
more information.
NOTE: If you have problems with this configuration, perhaps it is a
consequence of the last USB driver checking (r4359)
usbmsc:
-------
This configuration directory exercises the USB mass storage
class driver at system/usbmsc. See examples/README.txt for
more information.
NOTE: If you have problems with this configuration, perhaps it is a
consequence of the last USB driver checking (r4359)