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 loaders/arm-cma230/gdbload.bin under the root of your eCos installation.
The EPROM is installed to socket U3 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 little-endian, which is usually the default in PC based programmer software.
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.
Pre-built GDB stubs images are provided in the directory loaders/arm-cma230 relative to the root of your eCos installation, but here are instructions on how to rebuild them if you should ever need to.
CygMon images are prefixed with the name 'cygmon' and GDB stub ROM images
are given the prefix 'gdb_module'. Images may be provided in a number of formats including ELF (.img extension), binary (.bin extension) and SREC (.srec extension).
1. Start with a new document - selecting the File->New menu item if necessary to do this.
Choose the Build->Templates menu item, and then select the ARM CMA230 hardware.
While still displaying the Build -> Templates dialog box, select the "stubs" package template to build a GDB stub image. Click OK.
Build eCos using Build -> Library
When the build completes, the image files can be found in the bin/ subdirectory of the install tree. The GDB stub ROM images have the prefix "gdb_module".
1. Make an empty directory to contain the build tree, and cd into it.
To build a GDB stub ROM image, enter the command:
$ ecosconfig new cma230 stubs |
Enter the commands:
$ ecosconfig tree $ make |
When the build completes, the image files can be found in the bin/ subdirectory of the install tree. The GDB stub ROM images have the prefix "gdb_module".