As with the -i386 port, .../sparc_elf/crt0.c needs to be
compiled with -O2 or less optimization, or the static
keyword has to be eliminated from the front of the
___start prototype and function declaration.

Otherwise:

cc -o buffer buffer.o sem.o
/usr/lib/crt0.o(.text+0x28): undefined reference to `___start'
collect2: ld returned 1 exit status

        Sean.