Local.conf - simple questions

Hello all,

I am seeing this in local.conf:

# Enable a serial console on the USB CDC ACM ttyGS0 too
SERIAL_CONSOLES_colibri-vf = "115200;ttyLP0 115200;ttyGS0"

Since I am building for colibri-imx6, should the above be modified? USB serial console works, I am just curious.

Also, I note that for IMAGE_INSTALL_append = " qtbase…" it is advised to insert a space before qtbase (in this instance), but for IMAGE_INSTALL_remove, no space ever appears to be used - why is this?



The Yocto Documentation, particularly the Complete Documentation Set and the Bitbake Users Manual provides a lot of information on these kind of questions.

Two books I can recommend are:
Embedded Linux Development with Yocto Project
Embedded Linux Projects Using Yocto Project Cookbook

Well that depends on what you want to do. If you want to spawn a login terminal on the USB serial connection then yes, you might want to set SERIAL_CONSOLES. If you want to make use of the serial gadget from within your own program you likely do not.

Note that the imx UART driver creates /dev/ttymxcX, not /dev/ttylpX.

The _append operator appends to the string already contained in a variable without adding whitspace. So

GREETING_append = "there"

results in GREETING containing “Hithere”.

So it is likely that you want a leading whitespace with _append or a trailing whitespace with _prepend.

The _remove operator on the other hand searches the given word (or whitespace delimited words) in a variable and if they exist removes them. So no leading or trailing whitespace is needed for _remove.


Thanks, I shall take a look at the books you recommend when I get a little time.

Actually, re: SERIAL_CONSOLES_colibri-vf, what I was really asking was - should this be defined as e.g. SERIAL_CONSOLES_colibri-imx6, since it is the Colibri iMX6 I am using? Or is this irrelevant?

Like I say, the USB serial port is working fine, so this is not a major issue!

The move to the _colibri-imx6 override I assumed implicitly in my answer.

If you need a serial getty spawned on Colibri iMX6 you could define
SERIAL_CONSOLES_colibri-imx6 = “115200;ttymxc0 115200;ttyGS0”.