Another possiblity is to install a base system, modify the bootloader, put a getty on serial, and pray. Not that I've tried this.
That is actually what I did but the base system is the Cobalt 2 OS. I have to follow a portion of their procedure up until the Init process because the bootp, nfs mounting and kernel loading is done from eprom which at this time I cannot reprogram (nor do I want to). After that it is all shell scripts and Perl which handle the OS reload.
What on the standard debian installation takes care of partitioning and package installation?