fd = cfs_open("contiki.cfg", CFS_WRITE);
fd = cfs_open(strcat(kfs_getdir(), "contiki.cfg"), CFS_WRITE);
config_save(void){  int fd;  fd = cfs_open("contiki.cfg", CFS_WRITE);  if(fd == -1) {    return;  }  cfs_write(fd, &config, sizeof(config));  cfs_close(fd);}