Mine

venus# make
/usr/pkg/bin/xsltproc
Building OpenBIOS on  for 
Cleaning up... ok
Initializing build tree...ok.
Creating target Makefile...ok.
Creating config files...ok.
Building...error:
make: Unknown modifier '%'
make: Unknown modifier '%'
gcc -O2 -g -Wall -W -DFCOMPILER -DBOOTSTRAP  -Iinclude -Ikernel/include -Iobj-sparc32/target/include -c -o obj-sparc32/host/kernel/bootstrap.o 
gcc: no input files
*** Error code 1

Stop.
make: stopped in /home/earth/Desktop/openbios-devel