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diff --git a/examples/embedding/README.md b/examples/embedding/README.md new file mode 100644 index 0000000000..989ce1fc8f --- /dev/null +++ b/examples/embedding/README.md @@ -0,0 +1,67 @@ +Example of embedding MicroPython in a standlone C application +============================================================= + +This directory contains a (very simple!) example of how to embed a MicroPython +in an existing C application. + +A C application is represented by the file hello-embed.c. It executes a simple +Python statement which prints to the standard output. + + +Building the example +-------------------- + +Building the example is as simple as running: + + make + +It's worth to trace what's happening behind the scenes though: + +1. As a first step, a MicroPython library is built. This is handled by a +seperate makefile, Makefile.upylib. It is more or less complex, but the +good news is that you won't need to change anything in it, just use it +as is, the main Makefile shows how. What may require editing though is +a MicroPython configuration file. MicroPython is highly configurable, so +you would need to build a library suiting your application well, while +not bloating its size. Check the options in the file "mpconfigport.h". +Included is a copy of the "minimal" Unix port, which should be a good start +for minimal embedding. For the list of all available options, see +py/mpconfig.h. + +2. Once the MicroPython library is built, your application is compiled +and linked it. The main Makefile is very simple and shows that the changes +you would need to do to your application's Makefile (or other build +configuration) are also simple: + +a) You would need to use C99 standard (you're using this 15+ years old +standard already, not a 25+ years old one, right?). + +b) You need to provide a path to MicroPython's top-level dir, for includes. + +c) You need to include -DNO_QSTR compile-time flag. + +d) Otherwise, just link with the MicroPython library produced in step 1. + + +Out of tree build +----------------- + +This example is set up to work out of the box, being part of the MicroPython +tree. Your application of course will be outside of its tree, but the +only thing you need to do is to pass MPTOP variable pointing to +MicroPython directory to both Makefiles (in this example, the main Makefile +automatically passes it to Makefile.upylib; in your own Makefile, don't forget +to use a suitable value). + +A practical way to embed MicroPython in your application is to include it +as a git submodule. Suppose you included it as libs/micropython. Then in +your main Makefile you would have something like: + +~~~ +MPTOP = libs/micropython + +my_app: $(MY_OBJS) -lmicropython + +-lmicropython: + $(MAKE) -f $(MPTOP)/examples/embedding/Makefile.upylib MPTOP=$(MPTOP) +~~~ |