I don't believe they are just sitting out there like open source. I believe you will have to purchase this libraries. Just like you. However, the problem boi

I don't believe they are just sitting out there like open source. I believe you will have to purchase this libraries. Just like you. However, the problem boils down to the fact that you will be developing on custom hardware, thus the libraries will probably not be reusable. Basically you have to prove that all lines of code are part of the requirements, no dead code. You will also have to prove that all code fails in a fail safe manner. I.e. the plane won't crash Level A cert is for flight critical systems, I.e. flight controls.