Writing peripheral initialization code is probably the most tedious work in embedded development. It always successfully stops me from starting a new project. I believe engineers at STMicroelectronics share the same pain. Therefore they created STM32Cube firmware and STM32CubeMX graphical configuration tool, which turns numerous key strokes and page flips into just a few mouse clicks. STM32CubeMX is free software, but the initialization code it generates require compiler tools carrying hefty price tags, IARARM, Keil ARM-MDK, and Atollic TrueSTUDIO, to name the few. Fair enough these compilers do offer free editions with limited functionality. But I still prefer unrestricted, free tool that is easily scale-able for my current and future projects. Just like the GNU Make and ARM GCC toolchain I described in Opensource STM32 development.