Porting Python to an embedded system

Question

I am working with an ARM Cortex M3 on which I need to port Python (without operating system). What would be my best approach? I just need the core Python and basic I/O.

Answer 1

There are a few projects that have attempted to port Python to the situation you mention, take a look at python-on-a-chip, PyMite or tinypy. These are aimed at lower power microcontrollers without an OS and tend to focus on slightly older versions of the Python language and reduced library support.

Answer 2

fyi I just ported CPython 2.7x to non-POSIX OS. That was easy. You need write pyconfig.h in right way, remove most of unused modules. Disable unused features. Then fix compile, link errors. Then it just works after fixing some simple problems on run. If You have no some POSIX header, write one by yourself. Implement all POSIX functions, that needed, such as file i/o. Took 2-3 weeks in my case. Although I have heavily customized Python core. Unfortunately cannot opensource it :(.

After that I think Python can be ported easily to any platform, that has enough RAM.

Answer 3

Compile it to c :)

http://shed-skin.blogspot.com/

Answer 4

You should definitely look at eLua:

http://www.eluaproject.net

"Embedded power, driven by Lua Quickly prototype and develop embedded software applications with the power of Lua and run them on a wide range of microcontroller architectures"

Answer 5

Golly, that's kind of a tall order. There are so many services of a kernel that Python depends upon, and that you'd have to provide yourself. I'd think you'd be far better off looking for a lightweight OS -- maybe Minix 3? -- to put on your embedded processor.

Failing that, I'd be horribly tempted to think about hand-translating to C and building the essentials on that.

Answer 6

One possible approach is to build your own stack machine in software to interpret and execute Python byte code directly. Certainly not a porting job and quite labor-intensive to implement, but a self-contained Python byte code stack processor built for your embedded system gets you around needing an operating system.

Another approach is writing your own low level executive (one step below a general purpose OS) that contains the bare minimum in services that a core Python interpreter port requires. I am not certain if this is more or less labor intensive than building a stack processor.

I am not recommending either of these approaches - personally, I like Charlie Martin's Minix 3 approach best since it is a balanced requirements compromise. On the other hand, what I suggest might be interesting if your project absolutely requires Python without an operating system and if the project has an excellent time and money budget.

Update 5 Mar 2012: Given a strict adherence to your Python/No OS requirements, another possibility of a path to a solution may lie in using an OS-less Java VM (e.g., jnode, currently in beta) and use Jython to create Java byte code from Python. Certainly not an ideal off-the-shelf solution, and it does seem to meet an OS-less Python requirement.