well depending on what you need for your mini map, will play a factor of how much code is need and if it reads realtime or as a player move along and if it stores the info for your mapping system or it just shows the perimeter of player at a location. ethier way your need a array for it to read from...
I have two ideas, 1st would be by just making your maps and all the details then take each part and slowly draw them onto your map one at a time, or 2 if you want to make it show real time player movement (which is easy), can be done by just adding a sprite on the bottom screen then take its x/y and inc/dec when the player moves, but only hard thing is finding the exact speed to put it but can by
