I can't see an architecture doc, or other docs describing the build toolchain. Since pypy doesn't use commonly used build tools (or does it?) porting is going to be harder than something that uses a well know build toolchain like autotools/cmake/etc for example.

What would a high level porting strategy be? Get it running on CPython first, run tests..., set up platform specific details in files X,Y,Z, then try and translate? Perhaps the people who did the ARM port could write a short post on the strategy they took? What things can you disable to get a minimal pypy working first?

CPython has a short Porting document of which the style could be mostly copied and improved on with pypy specific details. https://github.com/python-git/python/blob/master/Misc/Portin...

I like the "Bang on it until you get a >>> prompt" :)