fdf2reg converts a readable ?.reg file to a .fdf registry initialization file (as default.fdf).
you have to specify with '-3' or '-4' if you want to create a wince3.x or wince4.x format file.
with '-s' you can specify a desired fixed size of the output file. this is useful when you want to override the default.fdf in a ppc2003 xip block, and want to be able to update this block using updatexip.