how to link .o

[zhonglei]

hi 
  In my module htm.c , I use the a set of API function in bestcomm.o.
I include the bestcomm.h in htm.c and in makefile I write:
ppc_82xx-gcc -c htm.c .
when I insmod htm.o , the "unresolved symbol" error happens because there is no definition of the function.

My question is: 
What command should I write in makefile to link the bestcomm.o into my htm.o to make the function defined?
BestRegards
zhonglei