Have a look at <http://rsphy1.anu.edu.au/~gpg109/mem.html>, which gives details on a 1.09 kernel that can run on machines with a megabyte of real memory. Even if there's some reason that you need 2.0 rather than 1.09, it lists some of the things that were done to the standard 1.09 kernel, which you may also be able to apply to 2.0.