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 boards/arm/lpc17xx_40xx/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_SYSTEM_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"
