The manual page for cdboot says: If no commands are given for a short time, cdboot will then attempt to load an OpenBSD kernel from the CD. It first looks for the install kernel bsd.rd in the standard amd64 release directory (e.g. /3.6/amd64/bsd.rd), then for /bsd.
This doesn't seem to match the observed behaviour - if /bsd.rd is not found, it drops to a boot prompt... -- Tati Chevron Perl and FORTRAN specialist. SWABSIT development and migration department. http://www.swabsit.com