I have uboot working with debug output on ttyS0. I have another device that I want to send some bytes to attached to ttyS2. In other words, I need access to two serial ports at the same time while running uboot. Is there any example of modifying the source to have access to that serial port? Or, even better, a way to do something from the uboot environment commands. Something like
echo "foo\n" > ttyS2
would be ideal (like one could do in userspace).
In terms of the uboot source, I’ve poked around a bit and there seems to be these device model serial ports that can be configured, but with all of the various configurations, I am not sure where/how I need to configure these.
Not sure why that response was marked as an accepted answer… Neither of those posts answer the question asked. They just give some help on how to statically assign the serial port used by uboot for debug output… My question is how to dynamically access various serial ports from either the uboot environment scripts or in the source code itself.
If you are disabling serial console in U-Boot this may be of use:
[url]https://devtalk.nvidia.com/account/message/71039/post/5196289/#5196289[/url]
One reason for mentioning this is that if you want to use ttyS0 for something else it has to first be disabled as serial console. Another reason is that you might find the reverse of this to be similar for your case…just not with debug output. I have not set up alternate serial port use in U-Boot so it is difficult to answer exactly.
Definitely appreciate the input, just don’t want this to be marked as answered until it actually is. Maybe someone out there has done this before :)