A part of answer is :
For reference, Maemo Mapper uses the exact same tile structure as Google Maps. The directory structure itself is defined as "map_cache_dir/zoom/x/y.jpg". For example, file "map_cache_dir/12/5/10.jpg" maps to "http://mt.google.com/mt?n=404&v=w2.999&x=5&y=10&zoom=12". So if you can figure that out, then you can produce maps that will work in Maemo Mapper.
By the way, Maemo Mapper also supports PNG, or any other format that is recognizable by gdk_pixbuf. The names of the files must have the .jpg extension ...

I hope it'll help you.
If you find a solution, please help me.