Running eCos on the OpenRISC ordb2 board


UPDATE: the eCos for OpenRISC is now tracking mainline eCos and more configurations are tested, so the whole procedure was a bit simplified!

Downloading the new version of eCos will be described in a new note and linked to here.

Antmicro is maintaining and developing the eCos port for OpenRISC – you can find the wiki page of the port at the opencores server.

So far, the port was being tested in the or1ksim simulator which is considered a golden model of the OpenRISC1000 architecture. However, it’s always best to see how a port performs on real hardware.

Recently, ORSoC shared the new ordb2 development board with us. The board is based on Altera Cyclone IV E FPGA chip and is equipped with all popular interfaces.

To verify that everything works fine, we tested the eCos port on the board by running a set of eCos tests and simple multi-threaded programs.

Below are the instructions how to run eCos programs on ordb2 board. UPDATE: Not all configuration options are yet supported, but the default configuration is well tested and stable, so the .ecc file provided previously is no longer needed.

In order to build eCos for ordb2, follow these instructions:

mkdir ecos_openrisc
cd ecos_openrisc
ecosconfig new orpsoc
ecosconfig tree
make tests

After issuing these commands it is possible to run eCos tests on the board. In order to upload the binaries using GDB, the or_debug_proxy program is needed.

Please note that FT4232 support was added to or_debug_proxy on 16th september 2011 – older builds will not work.

To establish a connection with board, issue the following command:

or_debug_proxy -r 50001

This will open a tcp port for the GDB RSP connection.

It is now possible to open a UART connection. Please note that it is better to open the UART connection after starting or_debug_proxy. It is because or_debug_proxy causes the system to reorder USB devices when connected to the FTDI chip.

The configuration file assumes that the UART is running at a 115200 baud rate.

To open a UART device using picocom, issue the following command:

picocom -b 115200 /dev/ttyUSB1

The number next to ttyUSB may be different across systems.

Everything is ready to upload a test binary. We will use GDB and connect to or_debug_proxy.

or32-elf-gdb [test binary]
target remote :50001
spr npc 0x100

Now that we know how to connect to the board, let’s make a simple hello world application. A minimal eCos hello world program looks pretty standard:

#include <stdio.h>
int main(void) {
  printf("hello world\n");
  return 0;

To build the program, use the following flags with or32-elf-gcc:

or32-elf-gcc \
   -g \
   -Iecos_openrisc/install/include \
   -Lecos_openrisc/install/lib \
   -nostdlib \
   -Tecos_openrisc/install/lib/target.ld \\

It is now possible to upload the resulting binary file the same way described above. Have fun programming for eCos on the openRISC devboard!