configtool error

Yes, you're right. It'd be a useful addition to the documentation if we listed the minimal system requirements. However the list of required devices is pretty small.

Apart from the processor itself, sufficent memory and a boot device (e.g. flash), the only device that must be present is a timer. This needs to be capable of periodically interrupting the processor (i.e. the interrupt line needs to be connected), and the default period needs to be something sensible (e.g. 10 ms).

Of course, if you want console I/O you will need to add in a console device etc. etc.