I've been working on my final year project using the GNU ARM Eclipse plugin and the STM32F4 Discovery board to write some simple signal generation software. Eclipse has a button to reset the target and restart debugging on the toolbar, and I figured it would also download a new binary if there was one. Unfortunately it doesn't, and I couldn't find any explanation how to start debugging, find a problem, make a change, recompile and reload the software without stopping and restarting the debugger, which isn't all that quick.

Turns out its really easy, at the bottom of the Startup tab in the Eclipse Debug Configurations box is a space for commands to run after a reset, and it looks like that's run when you hit the reset and restart button too. The commands I used were:

symbol-file C:\\\\Users\\\\Sam\\\\...someotherstuff...\\\\Debug\\\\projectname.elf
load C:\\\\Users\\\\Sam\\\\...someotherstuff...\\\\Debug\\\\projectname.elf

It looks like the double backslash is important to escape the path properly, and obviously I've changed the path and remove the project name to protect the guilty!

Hope that helps someone, or possibly me if I forget how to do this!