>>there's no screen on a microcontroller so printf("hello world") does nothing. The article is specifically about ARM Cortex-M4s, which support semihosting. So

>>there's no screen on a microcontroller so printf("hello world") does nothing. The article is specifically about ARM Cortex-M4s, which support semihosting. So most of the tools listed in the article will just automatically spit printf out to the semihosting console without any effort. Even if there isn't semihosting on a platform, the first thing I almost always do with board bring-up is pipe printf to some debug port (uart, ethernet, usb, etc).