naresetapp: Soft Reset Application

SUMMARY:

  This example application demonstrates a very simple method
  for polling a GPIO input signal to initiate a soft reset
  of the firmware.  Such a method could be used, for
  instance, to react to the pressing of a pushbutton
  connected to one of the GPIO pins on the processor.

  The example will:

    1. Configure the named GPIO pin as an input
    2. Read the state of the named pin
    3. If the appropriate bit is set to the
       configured value, a soft reset is initiated
    4. If not, the example loops

  NOTE: This is not intended to be an example
        of an efficient means to implement the
        polling of a GPIO input... just to very
        simply introduce the syntax used to extract
        GPIO data from the registers.


APPLICABILITY:

  This example could be used in conjunction with any
  development platform with minor modifications.

  It is ideally suited, however, for use with
  the following hardware platforms:

    Digi Connect ME
    Digi Connect EM
    Digi Connect SP


HARDWARE SPECIFIC NOTES:

  The Digi Connect ME, WiME, EM, WiEM, SP, and WiSP all have the same GPIO pin
  available... pin 5 of PORTC.  These boards name this pin
  "/INIT".  As a result of this commonality, the example uses
  this GPIO location as the default.

  In the Digi Connect ME and WiME the "/INIT" line is exposed on
  the 20 pin header at pin 20.  When connected to the ME or WiME
  development board, it is wired to the jumper block P12.
  It is normally pulled high; with a jumper across pins
  2 and 3 of block P12 it is forced low.

  In the Digi Connect EM, WIEM, SP and WiSP the "/INIT" line is connected
  to the push button on the module (SW1, it is not reset button (SW5) on the 
  development board).

  The define RESET_VALUE in root.c determines whether action should be 
  taken if the selected input reads as "low" or "high", respectively.

BUILD INFORMATION:

  One GNU make file is provided.  Build the target 'image.elf' to
  generate an image that can be debugged with gdb, and the file 
  image.bin which can be written to flash.

  The following files are provided in this example:

    appconf.h         sets application configuration settings
    makefile          Make file for the GNU toolset.
    readme            this file
    root.c            contains applicationStart() function

  The application build file links in the following libraries:

    libbsp.a       contains the BSP code
    libdnsclnt.a   contains the DNS client library
    libfastip.a    contains the Fast IP library
    libflash.a     contains the Flash driver API library
    libposix.a     contains the POSIX layer libraries
    libsntp.a      contains the SNTP client library
    libtcpip.a     contains the Net+Works TCP/IP stack
    libtx.a        contains the ThreadX kernel

  The application uses the following file located in the
  netos\src\linkerScripts directory.  This file is generated
  when the BSP is built.

image.ldr       GNU linker script used to build an image that can
                be debugged and used with the bootloader.
                
customize.ldr   Customizable GNU linker script

