binpatch-ing problem! please help

[email protected] Mon, 18 May 2009 20:12:30 +0200 (CEST)
Newsgroups gmane.os.netbsd.ports.atari
Message-ID <[email protected]>
How to extend st-mem pool?
I tried this:
binpatch -s st_pool_size -o 8192 -r 131072 /netbsd
and i got:
can't open file  or  not a valid executable

I'm stuck, please help