phyFLEX
®
-i.MX 6
If you are not logged in, enter
root and press Enter.
Type .
/myHelloWorld to start the application.
You will see the following output:
.Welcome to the World of PHYTEC! (serial).
.Welcome to the World of PHYTEC!.......... .
Close Microcom.
When you start the application via an SSH session, you only see one output line. When you
execute the program with Microcom, you see two output lines.
The first line is a direct output on the serial interface. You can not see this
line in an SSH session, because you are connected over a TCP/IP
connection to the target. With Microcom, however, you have direct access
to the serial interface, so you can also see the line that is written to the
serial console.
In this section you have changed an existing application. You also learned
how to access the serial interface. First you called the function open() on
the device /dev/console. The return value of this function was a file
descriptor. With the file descriptor you called the function write() to send
n bytes to the device /dev/console. After that, the file descriptor was
closed with the function close().
This procedure is quite typical for Linux, because Linux treats everything
as a file.
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PHYTEC Messtechnik GmbH 2015 L-781e_7
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