Serial Connections
There are several ways to connect to a system running EMAC OE Linux. The preferred connection method depends on the capabilities of the hardware. For example, headless systems (those without a graphical interface) will most likely use a serial port console, while systems with a video connection may be accessed using a keyboard and LCD or monitor. When an LCD or monitor is available, a serial connection can occasionally still be needed; usually, this need arises after a user has accidentally misconfigured the display. Other times, it may be useful to be able to use a serial console on a board that's running remotely but has had its network connection drop out. The serial console can be a very useful tool for diagnosing and debugging issues even after development has finished.
Serial Terminal
A serial terminal connection is most commonly the first connection that will be made to a system in its default configuration. A serial terminal application such as Minicom for Linux or PuTTY under Windows is required for this connection. The serial cable type, port, and communication parameters for each system type are listed in Table 1 below.
| SoM | Port | Cable Type | Baud Rate | Data Bits | Parity | Stop Bits | Flow Control |
|---|---|---|---|---|---|---|---|
| 200 Pin SoM's | COMB | NULL Modem | 115200 | 8 | None | 1 | None |
| 144 Pin SoM's | COME | NULL Modem | 115200 | 8 | None | 1 | None |
| SOM-9260 | COMA | NULL Modem | 115200 | 8 | None | 1 | None |
| SOM-9G20 | COMA | NULL Modem | 115200 | 8 | None | 1 | None |
| iPac-9x25 | HDR4 | NULL Modem | 115200 | 8 | None | 1 | None |
| x86 Boards | * | * | * | 8 | None | 1 | None |
 | * : These settings vary among x86 systems. Refer to the system manual for the target board for more information. Not all x86 systems have a serial terminal connection enabled by default. |
Follow the steps below to establish a serial connection:
- Connect a serial cable between the serial port on the workstation and target board and start a terminal application.
- Setup the communication parameters for your board according to Table 1.
- Connect power to the target board; boot messages will begin to print within a few seconds.
- When the board has finished booting a login prompt will appear.
| Note that boards that do not have the serial device set as the default kernel console (such as the majority of headed x86 systems) will not display boot messages over the serial port during boot without further configuration. In these cases, the login prompt will appear when the board has finished booting. If a login prompt does not appear, press enter in the serial terminal application several times. |
Next Steps
After you have established a connection with your device running EMAC OE Linux, you will need to log into the system.
