The eCos Developer’s Kit package comes with an EPROM
which provides GDB support for the Cogent
evaluation board. An image of this EPROM is also provided at
the root of your eCos installation. The same EPROM and image can
be used on all three supported daughterboards: CMA287-23 (MPC823),
CMA287-50 (MPC850), and CMA286-60 (MPC860).
The EPROM is installed to socket U4 on the board. Attention
should be paid to the correct orientation of the EPROM during installation.
If you are going to burn a new EPROM using the binary image,
be careful to get the byte order correct. It needs to be big-endian.
If the EPROM burner software has a hex-editor, check that the first
few bytes of the image look like:
If the byte order is wrong you will see 603c instead of 3c60
etc. Use the EPROM burner software to make a byte-swap before you
burn to image to the EPROM.
If the GDB stub EPROM you burn does not work, try reversing
the byte-order, even if you think you have it the right way around.
At least one DOS-based EPROM burner program is known to have the
byte-order upside down.
The GDB stub in the EPROM allows communication with GDB using
the serial port at connector P12 (CMA101) or P3 (CMA102). The communication parameters
are fixed at 38400 baud, 8 data bits, no parity bit and 1 stop bit
(8-N-1). No flow control is employed. Connection to the host computer
should be made using a dedicated serial cable as specified in the
Cogent CMA manual.