I just tested the communication of the MCU with OpenOCD. Judging from the output I received, I would say it was a success. Normally that would not really be worth mentioning. However, as this is an architecture - and also a toolchain - that is new to me and the first time I soldered this kind of package, I could not take the success of this step for granted. Now that the basics seem to work, I can move on to populating the rest of the PCB and writing some test programs.