I can compile, build and flash firmwares perfectly (until now) using these tools. But I do not know how to debug (toggle breakpoints, see sfr values, etc.) or even to "print" from CC2540.
Chapter 3 from CC2540 user guide talks about the debug interface, and reading it I notice that flash programming is done using this interface. So... aparently to debug the firmware I would have to extend cc-tool. It sounds right?
About printing: reading the sdcc user guide (section 184.108.40.206) I realize that I have to provide
putchar() function, which makes sense. But what low level protocol should I use? USART? Or something else? (debug interface?) How the CC2540 can talk with cc-debugger? How cc-debugger can talk with Ubuntu?
This all seems a little vague, but it is because I have no experience in this "field" (I always used Arduino and I never had to go in this "low level" before).