topic Re: Auto connect JLink when application start up in FreeMASTER

Auto connect JLink when application start up

LuBiq — Thu, 18 Dec 2025 02:43:16 GMT

I want to capture the initial state of the application. Is there any solution to make FreeMASTER connect target board immediately and automatically when application start up?

Re: Auto connect JLink when application start up

iulian_stan — Thu, 18 Dec 2025 16:28:06 GMT

Hi @LuBiq,

You can achieve this behavior by simulating a loop in the initialization phase of your application that would wait for a global variable (trigger).

After you connect to the target using FreeMASTER, you can change that variable value to continue application execution. Ex:

volatile char wait = 1; // Trigger variable (to be chnaged from FreeMASTER) void main() { while (wait) { // Wait for trigger to change } // Application logic }

Note: this approach will work only with BDM plugin as other plugins require some initializations before you'll be able to connect to the target.

Re: Auto connect JLink when application start up

LuBiq — Fri, 19 Dec 2025 01:22:41 GMT

I find a very simple solution.

(1) After building, start the application via debug. The application will be suspended at the first code in main() by a breakpoint.

(2) Start communication in FreeMASTER.

(3) Disable all breakpoints, application begins to run.

Can this solution meet my requirement?