when you run chroot you specify what you run in chroot
i.e. chroot /path/to/chrootdir /run/me
Usually /run/me is /bin/bash or whatever (relative to the chrootdir) - change to what you want to run. You can specify a script, that is contained within chroot, that runs more than one binary within the same chroot.
At least this is what I do on a dd-wrt router (arm) to run full non-crippled binaries if optware is not enough.