To build yourself an image for your DM7025 you need a little more than cvs :-)
follow these instructions:
h**p://developer.elitedvb.net/listprojects.php?curr_dir=81
Prerequisite: a Makefile (from link above) and tool Monotone 0.24 or 0.25
Everything from toolchain compiler to packages will be downloaded (with rsync and cvs) and built from scratch.
My advice is a nice book or movie because the first build process needs a lot of time (hours).