README.txt
This README file discusses the port of NuttX to the PiKRON LX_CPU board: See http://pikron.com/pages/products/cpu\_boards/lx\_cpu.html. This board features the NXP LPC4088 MCU
CONTENTS
o LEDs o Serial Console o ETHERNET o Using OpenOCD with the Olimex ARM-USB-OCD o Loading Code with the ISP Board o Configuration
LEDs
The LX_CPU base board has two user LEDs
LED1 : Connected to P1[29] RED
LED2 : Connected to P0[16] GREEN
If CONFIG_ARCH_LEDS is not defined, then the user can control the LEDs in any way using the definitions provided in the board.h header file.
If CONFIG_ARCH_LEDs is defined, then NuttX will control the 2 LEDs on the WaveShare Open1788K. The following definitions describe how NuttX controls the LEDs: LED1 LED2 LED_STARTED OFF OFF LED_HEAPALLOCATE ON OFF LED_IRQSENABLED OFF ON LED_STACKCREATED ON ON LED_INIRQ LED_SIGNAL LED_ASSERTION LED_PANIC LED_IDLE
Serial Console
By Default, UART0 is used as the serial console in all configurations. This may be connected to your computer via an external RS-232 driver or via the WaveShare USB ISP/VCOM module.
As an option, UART1 can also be used for the serial console. You might want, to do this, for example, if you use UART0 for the ISP function and you want to use a different UART for console output. UART1 can be configured as the serial console by changing the configuration as follows:
System Type:
CONFIG_LPC17_UART0=n : Disable UART0 if it is no longer used
CONFIG_LPC17_UART1=y : Enable UART1
Drivers:
CONFIG_UART1_SERIAL_CONSOLE=y : Setup up the UART1 configuration
CONFIG_UART1_RXBUFSIZE=256
CONFIG_UART1_TXBUFSIZE=256
CONFIG_UART1_BAUD=115200
CONFIG_UART1_BITS=8
CONFIG_UART1_PARITY=0
CONFIG_UART1_2STOP=0
In this configuration using UART1, it is necessary to disable LED support on the board. That is because UART1 RXD is set for pin p0.16, but so is LED2. If you do not disable LED support then no incoming serial data will be received.
Common Board Options
CONFIG_ARCH_LEDS=n : Disable LED support
You should also remove the LED2 jumper so that the RXD input does not attempt to drive LED2 as well (However, this does not seem to interfere with data receipt).
NOTE: If you intend to use LEDs with UART1, then you might want to redesign some of the LED logic in the src/ subdirectory so that it does not attempt to use LED2.
ETHERNET
On chip ethernet MAC with external 10/100M PHY DP83848I. The LX_CPU board is populated with integrated connector module (ICM) socket suitable for direct connection to the standard ETHERNET infrastructure.
Config CONFIG_LPC17_ETHERNET=y CONFIG_LPC17_PHY_AUTONEG=y CONFIG_ETH0_PHY_DP83848C=y
Using OpenOCD with the Olimex ARM-USB-OCD
Building OpenOCD under Cygwin:
Refer to Documentation/platforms/arm/lpc17xx/boards/olimex-lpc1766stk/README.txt
Installing OpenOCD in Ubuntu Linux:
sudo apt-get install openocd
Helper Scripts.
I have been using the Olimex ARM-USB-OCD debugger. OpenOCD
requires a configuration file. I keep the one I used last here:
boards/arm/lpc17xx_40xx/lx_cpu/tools/lx_cpu.cfg
However, the "correct" configuration script to use with OpenOCD may
change as the features of OpenOCD evolve. So you should at least
compare that lx_cpu.cfg file with configuration files in
/usr/share/openocd/scripts. As of this writing, the configuration
files of interest were:
/usr/local/share/openocd/scripts/interface/openocd-usb.cfg
This is the configuration file for the Olimex ARM-USB-OCD
debugger. Select a different file if you are using some
other debugger supported by OpenOCD.
/usr/local/share/openocd/scripts/board/?
I don't see a board configuration file for the WaveShare
LX_CPU board.
/usr/local/share/openocd/scripts/target/lpc1788.cfg
This is the configuration file for the LPC1788 target.
It just sets up a few parameters then sources lpc17xx.cfg
/usr/local/share/openocd/scripts/target/lpc17xx.cfg
This is the generic LPC configuration for the LPC17xx
family. It is included by lpc1788.cfg.
NOTE: These files could also be located under /usr/share in some
installations. They could be most anywhwere if you are using a
windows version of OpenOCD.
boards/arm/lpc17xx_40xx/lx_cpu/tools/lx_cpu.cfg
This is simply openocd-usb.cfg, lpc1788.cfg, and lpc17xx.cfg
concatenated into one file for convenience. Don't use it
unless you have to.
There is also a script on the tools/ directory that I use to start
the OpenOCD daemon on my system called oocd.sh. That script will
probably require some modifications to work in another environment:
- Possibly the value of OPENOCD_PATH and TARGET_PATH
- It assumes that the correct script to use is the one at
boards/arm/lpc17xx_40xx/lx_cpu/tools/lx_cpu.cfg
Starting OpenOCD
Then you should be able to start the OpenOCD daemon as follows. This
assumes that you have already CD'ed to the NuttX build directory:
. ./setenv.sh
oocd.sh $PWD
The setenv.sh script is a convenience script that you may choose to
use or not. It simply sets up the PATH variable so that you can
automatically find oocd.sh. You could also do:
boards/arm/lpc17xx_40xx/lx_cpu/tools/oocd.sh $PWD
Connecting GDB
Once the OpenOCD daemon has been started, you can connect to it via
GDB using the following GDB command:
arm-nuttx-elf-gdb
(gdb) target remote localhost:3333
NOTE: The name of your GDB program may differ. For example, with the
CodeSourcery toolchain, the ARM GDB would be called arm-none-eabi-gdb.
OpenOCD will support several special 'monitor' sub-commands. You can
use the 'monitor' (or simply 'mon') command to invoke these sub-
commands. These GDB commands will send comments to the OpenOCD monitor.
Here are a couple that you will need to use:
(gdb) monitor reset
(gdb) monitor halt
NOTES:
1. The MCU must be halted using 'monitor halt' prior to loading code.
2. 'monitor reset' will restart the processor after loading code.
3. The 'monitor' command can be abbreviated as just 'mon'.
After starting GDB, you can load the NuttX ELF file like this:
(gdb) mon halt
(gdb) load nuttx
NOTES:
1. NuttX should have been built so that it has debugging symbols
(by setting CONFIG_DEBUG_SYMBOLS=y in the .config file).
2. The MCU must be halted prior to loading code.
3. I find that there are often undetected write failures when using
the Olimex ARM-USB-OCD debugber and that if you start the program
with a bad FLASH failure, it will lock up OpenOCD. I usually
oad nuttx twice, restarting OpenOCD in between in order to assure
good FLASH contents:
(gdb) mon halt
(gdb) load nuttx
(gdb) mon reset
Exit GDB, kill the OpenOCD server, recycle power on the board,
restart the OpenOCD server and GDB, then:
(gdb) mon halt
(gdb) load nuttx
(gdb) mon reset
Other debuggers may not have these issues and such drastic steps may
not be necessary.
Loading Code with the ISP Board
Use can also load code onto the board using the WaveShare and the UART0 ISP/VCOM board. I use the FlashMagic program for Windows available here: http://www.flashmagictool.com/ . It is so easy to use that no further explanation should be necessary: Just select the LPC1788, the ISP COM port, and the NuttX .hex file and program it.
CONFIGURATION
nsh
Configures the NuttShell (nsh) located at examples/nsh. The Configuration enables only the serial NSH interface.
NOTES:
1. This configuration uses the mconf-based configuration tool. To
change this configuration 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./README.txt.
b. Execute 'make menuconfig' in nuttx/ in order to start the
reconfiguration process.
2. Uses the older, OABI, buildroot toolchain. But that is easily
reconfigured:
CONFIG_ARM_TOOLCHAIN_BUILDROOT=y : Buildroot toolchain
CONFIG_ARM_TOOLCHAIN_BUILDROOT_OABI=y : Older, OABI toolchain
3. This NSH has support for built-in applications enabled, however,
no built-in configurations are built in the defulat configuration.
4. This configuration has DMA-based SD card support enabled by
default. That support can be disabled as follow:
CONFIG_LPC17_GPDMA=n : No DMA
CONFIG_ARCH_DMA=n
CONFIG_LPC17_SDCARD=n : No SD card driver
CONFIG_SDIO_DMA=n : No SD card DMA
CONFIG_MMCSD=n : No MMC/SD driver support
CONFIG_FS_FAT=n : No FAT file system support
5. This configuration has been used for verifying SDRAM by modifying
the configuration in the following ways:
CONFIG_LPC17_EMC=y : Enable the EMC
CONFIG_LPC17_EXTDRAM=y : Configure external DRAM
CONFIG_LPC17_EXTDRAMSIZE=67108864 : DRAM size 2x256/8 = 64MB
CONFIG_TESTING_RAMTEST=y : Enable the RAM test built-in
In this configuration, the SDRAM is not added to heap and so is
not excessible to the applications. So the RAM test can be
freely executed against the SRAM memory beginning at address
0xa000:0000 (CS0).
6. This configuration has been used for verifying the touchscreen on
on the 4.3" LCD module.
a) As of this writing, this touchscreen is still not functional.
Rommel Marcelo has tracked this problem down to noise on the
PENIRQ interrupt. There are so many false interrupts that
the NuttX interrupt-driven touchscreen driver cannot be used.
Other compatible LCDs, however, may not have this issue.
b) You can enable the touchscreen by modifying the configuration
in the following ways:
Drivers:
CONFIG_INPUT=y : Enable support for input devices
CONFIG_INPUT_ADS7843E=y : Enable support for the XPT2048
CONFIG_ADS7843E_SPIDEV=1 : Use SSP1 for communication
CONFIG_SPI=y : Enable SPI support
CONFIG_SPI_EXCHANGE=n : exchange() method is not supported
System Type:
CONFIG_GPIO_IRQ=y : GPIO interrupt support
CONFIG_LPC17_SSP1=y : Enable support for SSP1
Library Support:
CONFIG_SCHED_WORKQUEUE=y : Work queue support required
Application Configuration:
CONFIG_EXAMPLES_TOUCHSCREEN=y : Enable the touchscreen built-int test
Defaults should be okay for related touchscreen settings. Touchscreen
debug output can be enabled with:
Build Setup:
CONFIG_DEBUG=y : Enable debug features
CONFIG_DEBUG_VERBOSE=y : Enable verbose debug output
CONFIG_DEBUG_INPUT=y : Enable debug output from input devices
c) You will also have to disable SD card support to use this test. The
SD card detect (CD) signal is on P0[13]. This signal is shared. It
is also used for MOSI1 and USB_UP_LED. The CD pin may be disconnected.
There is a jumper on board that enables the CD pin. OR, you can simply
remove the SD module so that it does not drive the CD pin.
Drivers:
CONFIG_MMCSD=n : No MMC/SD driver support
System Type:
CONFIG_LPC17_GPDMA=n : No DMA
CONFIG_LPC17_SDCARD=n : No SD card driver
CONFIG_SDIO_DMA=n : No SD card DMA
CONFIG_ARCH_DMA=n
File Systems:
CONFIG_FS_FAT=n : No FAT file system support
For touchscreen debug output:
Build Setup:
CONFIG_DEBUG=y
CONFIG_DEBUG_VERBOSE=y
CONFIG_DEBUG_INPUT=y
7. The button test (apps/examples/buttons) can be built-in by adding
the following options. See apps/examples/README.txt for further
information about the button test.
System Type:
CONFIG_GPIO_IRQ=y
Board Selection:
CONFIG_ARCH_BUTTONS=y
CONFIG_ARCH_IRQBUTTONS=y
Application Configuration:
CONFIG_EXAMPLES_BUTTONS=y
CONFIG_EXAMPLES_BUTTONS_MIN=0
CONFIG_EXAMPLES_BUTTONS_MAX=7
CONFIG_EXAMPLES_IRQBUTTONS_MIN=1
CONFIG_EXAMPLES_IRQBUTTONS_MAX=7
CONFIG_EXAMPLES_BUTTONS_NAME0="USER1"
CONFIG_EXAMPLES_BUTTONS_NAME1="USER2"
CONFIG_EXAMPLES_BUTTONS_NAME2="USER3"
CONFIG_EXAMPLES_BUTTONS_NAME3="JOYSTICK_A"
CONFIG_EXAMPLES_BUTTONS_NAME4="JOYSTICK_B"
CONFIG_EXAMPLES_BUTTONS_NAME5="JOYSTICK_C"
CONFIG_EXAMPLES_BUTTONS_NAME6="JOYSTICK_D"
CONFIG_EXAMPLES_BUTTONS_NAME7="JOYSTICK_CTR"