Hi, Sorry for not being around.
The reason for thinking about 'preparetoplay' is to make it easier to handle processes where you might want to be able to do some buffer flushing, or schedule a task and guarantee it happens before you process audio, like handing off pre-allocated resources or messages that have occurred in another thread.
An example of this would be, having a server running on the main CPU of bela that acts as a shared interface.
Perhaps a web page of tune-able controls. Is the safest way to pass those control values to the audio thread through a ring-buffer of mutex messages?
I could probably just stick with serving OSC messages between applications, but this is more a learning exercise, and such a feature would be more necessary if bela had dynamic buffer lengths. As it stands, I have a lot to learn about applications using shared memory space, and in-fact Linux in general.
As an aside, I am currently following this guide: http://clfs.org/view/clfs-embedded/arm/index.html for building linux distributions from scratch for ARM processors. Do you have any great resources for the specifics around building for BBB?
Cheers!