Access ETM of Nucleo F401RE without using a debug kit
Ok, then you want to ask a question.
By my knowledge and experience, certainly there are some other things to do.
First of all, how you want to connect to your ETM physically or electrically when you don’t want to use a debugger? Yes there are some of ways to do, but you need to decide and chose. Would you intend to configure your ETM output as UART style and then hook up a TTL serial to SWO? Or other ways.
Second, to firmware for STM32F401, as I mentioned, you need to write your own _write function to make the output to STD device to ETM, in order to use printf to write through ETM.
Do a search to get a big picture first, then ask a specific question, then people will be able to help.
-Andy