ошибки на командах

mknod /dev/ttyUSB0 c 188 0


stty -crtscts -hupcl 9600 < /dev/ttyUSB0

лог

root@DD-WRT:~# insmod ftdi_sio
root@DD-WRT:~# mknod /dev/ttyUSB0 c 188 0
-sh: mknod: not found
root@DD-WRT:~# chmod 666 /dev/ttyUSB0
root@DD-WRT:~# stty -crtscts -hupcl 9600 < /dev/ttyUSB0
-sh: can't open /dev/ttyUSB0: no such file
root@DD-WRT:~#