change CPPFLAGS= to CPPFLAGS+= - so that the definition of -DSERIAL in mbr/Makefile will not be overridden (seems like nobody is using a serial console)
change CPPFLAGS= to CPPFLAGS+= - so that the definition of -DSERIAL
in mbr/Makefile will not be overridden (seems like nobody is using
a serial console)

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars