Target Serial Access
It is useful to be able to get a terminal on your target device. This page lists some options for this. Instructions assume Ubuntu Lucid and a 115200 serial link. Also you should be using a serial null modem cable.
This is a common way of getting a serial port on a computer. See TRENDnet USB to Serial converter for example.
This is a convenient tool which allows you to 'telnet' into your board over a serial link. These instructions assume you are using a single USB serial dongle (/dev/ttyUSB0) but you can also use a real serial port (/dev/ttyS0) if you like. If you have an FTDI serial device providing serial access then it will use /dev/ttyACM0.
sudo apt-get install ser2net
Edit /etc/ser2net.conf and add this line:
4000:telnet:600:/dev/ttyUSB0:115200 8DATABITS NONE 1STOPBIT banner
Then restart so that ser2net sees your changes:
sudo /etc/init.d/ser2net restart
You can now connect to the board with:
telnet localhost 4000
To disconnect, press Ctrl-\ then Ctrl-D.
Screen is a useful tool for maintaining connections which you can switch between easily. It is often used to run a long-running job such that you can logout, then later login, reconnect and check progress. You can also use screen to get a serial link:
screen -t 'ttyUSB0 115200 8n1' /dev/ttyUSB0 115200,-ixoff,-ixon
Reset the machine and U-Boot should start printing to your terminal. For help, use Ctrl-A Ctrl-?. To disconnect, press Ctrl-A Ctrl-D and to quit the session Ctrl-A Ctrl-\
Minicom is a terminal program, intended for use with a modem, that works well as an intermediary to any remote system connect through a serial port. One big advantage of minicom is that it allows one to easily capture text into a file.
To install minicom, execute the following
sudo apt-get install minicom
sudo minicom -s
The configuration is done through a simple menu system. Use the options below for a basic working configuration.
Select 'Serial Port Setup' using the arrow keys; press <Enter> Select 'A': enter the name of your serial port. (ex: /dev/ttyUSB0) Select 'E': select 'E' (115200), then 'Q' (8N1) Set 'Hardware Flow Control' to 'No. Set 'Software Flow Control' to 'No'. Press <Enter>; this brings you back to the main menu (titled '[configuration]') Select 'Save setup as dfl'; press <Enter>. Select 'Exit from Minicom'; press <Enter>.
Minicom needs access to the configured serial port. This means you either need to change the permissions on that port to allow your normal user to access the port in read/write mode, or run using 'sudo'.
All commands are prefixed with <Ctrl-A>, which will be abbreviated C-a.
none <td> Key</td>
none <td> Result</td>
none <td>C-a Z </td>
none <td>Opens interactive menu</td>
none <td>C-a C </td>
none <td>Clear Screen</td>
none <td>C-a L</td>
none <td>Prompt for capture log file name.</td>
none <td>C-a L</td>
none <td>(after opening log file) Pause or close log file</td>
none <td>C-a Q </td>
none <td> Quit (w/o modem reset)</td>
none <td>C-a X </td>
none <td> Quit immediately</td>
none <td>C-a E</td>
none <td>Toggle echo of locally typed characters</td>
none <td>C-a W </td>
none <td>Toggle Line Wrap </td>
none <td>C-a T </td>
none <td>Select terminal settings</td>
Once you have network access, and assuming you are using a test build, you can use ssh to connect to your target.
ssh firstname.lastname@example.org (password test0000)