RTT logging from application started by bootloader

[Jacob]

Hello, Is it possible to get logs (RTT) from an application started by a bootloader? As of now I don't get anything after the bootloader has jumped to the application start address.

If I run the application separately it works.

Thanks, Jacob

[butch]

Can you provide more information about what you tried? Did you call SEGGER_RTT_Init() in your code and did you start the GDB server and the JLinkClient? I don't have any experience with boot loaded code, just with RTT using the debugger to load code.

[Hung Bui]

Did you also turn on RTT logging in the bootloader ?

[Jacob]

RTT logging from the bootloader works (and is apparently turned on). RTT logging from the application works if I run it standalone, but if I start it from the bootloader I don't get any output.

Will try SEGGER_RTT_Init(). Thanks.

[Hung Bui]

Hi Jacob,

When I tested here (SDKv13), it seems that when we reinit the log module we will actually open another RTT channel.

So if I open RTT client when the application running, I can only capture the RTT log from the application, even if I reset the device and the device enter the bootloader before it get to the application.

If I open RTT client when the bootloader is running and enterred bootloader mode, then I can follow the RTT client of the bootloader.

Do you really need RTT to be ON on the bootloader ? If you turn it off can you get RTT log on the application ?

[Jacob]

Hello, When developing boot issues it is very helpful to get output from both the bootloader and the application. Can I get the output from the second RTT channel then?

Thanks, Jacob