How does Kickstart actually start?

[Bob Arendt <rda@xxxxxxxxxx>]

This is more of a theory question - please feel free to redirect
me to a more appropriate list.

I'm setting up a kickstart install.  I can see how the initial kernel
line has a "ks" or "ks=nfs:server.example.com:/mydir/ks.cfg" parameter,
but what actually executes this information?  I can't find anything
in the kernel source that actually executes this.

How does kickstart really start?  Where's the relevant source code?

Thanks - Bob Arendt