Without CMOS I think we are limited to a single image, i.e. no fallback. So HAVE_OPTION_TABLE = 0 would imply HAVE_FALLBACK_BOOT = 0, and this part can be disregarded:
(accounting for the fact that the fallback image, in which USE_OPTION_TABLE=0, may also need to be able to read the 'boot byte' of the CMOS)
------------------------------------------------------------------------ Steven J. Magnani "I claim this network for MARS! www.digidescorp.com Earthling, return my space modulator!"
#include <standard.disclaimer>