Are you using a recent Beagleboard image? Beaglebone?
I haven't used libpruio, but I assume it uses the UIO kernel driver.
First, you will need to activate that driver.
This utility will help get it done:
You will need to clone the above to your board and make 2 very easy changes to text files.
Then you have to run the script in the above and re-boot.
Can perhaps guide you but need to know which kernel and which board you are using.
I didn't have to do anything to the Device tree for Remoteproc and PWM. Hopefully the same
will be true for UIO.
Regarding the PWM, once again, have to assume you are using a recent Debian image.
The version 4 kernels require some steps to get the PWM exported.
I did this just a few days ago, and got it to work. You need to look for:
/sys/class/pwm/pwmchip0
You need to export by something like:
echo 0 > export
Or it could be other numbers depending on which PWM.
I haven't found a concise reference for the above process, and how the export number maps to the particular PWM.
Perhaps someone else can point us to a good reference guide for this process.
Greg