hi After I post the previous letter, I tried this command: /configure --prefix=PREFIX --enable-sim then make all install. It build gdb all right under the building directory,but when I run the gdb I re-installed, it still don't accept the command "target sim".By the way, in the host there is anther gdb, I build gdb in my home directory. How to build a gdb with cgen-based gdb-sim? Thank u for ur help? Dam Wang _________________________________________________________________ Ãâ·ÑÏÂÔØ MSN Explorer: http://explorer.msn.com/lccn/