To test the hardware, the modifications, and the toolchain configuration, I have written a few short example programs. They demonstrate the use of the toolchain, how to set up a C runtime environment (using an assembly language entry point), how to access GPIO pins and thereby flash the LEDs, and how to use the serial port.
You can download the examples below as well as the newest hardware.h from Example Code.
A simple example demonstrating use of GPIO pins to flash some of the LEDs on the circuit board.
Another simple example, showing use of the serial port to transmit a text string. The com_putc, com_puts, and setup_com functions may be useful in many programs for displaying debugging information.
This example shows more complex use of GPIO and the serial port; data received over the serial port is displayed on a 16x2 character LCD attached to spare GPIO pins.