This describes the basics on building micropython binaries for different boards. In the examples below all builds were done on a Linux Mint 18.0 machine.
Prerequisites to this are setting up your build environment. You can get started and setup your build environment on Linux Mint 18.0 here
Assuming that you have a working environment and you can run make to make a build for Linux we can now explain the:
- directory structure
- making a build for an architecture
- flashing onto micropython hardware
Directory Structure
Building micropython for different hardware happens in the ports directory. If you look in:
~/microPython/project/micropython/ports
This contains a list of hardware platforms that are supported. At the time of writing, 14 in total. This document describes how to build for stm32 - the platform used by the micropython organisation. Which is in the stm32 subdirectory:
/ports/stm32
Within each platform directory there is build directory e.g.
/ports/stm32/build-PYBD_SF2
/ports/stm32/build-PYBD_SF6
When a build is complete the firmware builds are placed in the relevant directory. Within a build directory there are two main build files that are used to flash onto a board. Which are named firmware.hex and firmware.dfu. The dfu file is the file that has to be flashed onto your microcontroller.
Within the stm32 directory there is a modules directory. This is used to compile your own modules into a firmware build. This is explained later.
Making A Build For An Architecture
To make a build for a particular architecture you have to be in the specific hardware directory to run the make command. The make command can take many parameters, this document looks at building for a particular board and compiling into the firmware your own modules.
The format of the build command is make then [option] then [target]. For compiling against the new pyboard D-series the build targets are:
- PYBD_SF2
- PYBD_SF4
- PYBD_SF6
Hence you would comple for the SF2 like:
/> make BOARD=PYBD_SF2
And for the SF6 it would be:
/> make BOARD=PYBD_SF6
Compiling Your Own Python Code Into Firmware
To make a firmware build with a python file that you have created, simply place in the /modules directory the python file you wish to be available in your firmware build. Hence if you wanted to have a hello_world.py compiled into your firmware image do:
- place the hello_world.py into your /ports/stm32/modules directory
- do your build with the command **FROZEN_MPY_DIR=modules
e.g.
/> make BOARD=PYBD_SF2 FROZEN_MPY_DIR=modules
