sim_set_callbacks (&default_callback); default_callback.init (&default_callback);
if (gdbsim_desc != NULL) unpush_target (&gdbsim_ops);
gdbsim_open (args, from_tty)     char *args;     int from_tty;{  if (sr_get_debug ())    printf_filtered ("gdbsim_open: args \"%s\"\n", args ? args : "(null)");  sim_set_callbacks (&default_callback);  default_callback.init (&default_callback);  sim_open (args);  push_target (&gdbsim_ops);  target_fetch_registers (-1);  printf_filtered ("Connected to the simulator.\n");}