kopia lustrzana https://github.com/micropython/micropython
87 wiersze
3.0 KiB
ReStructuredText
87 wiersze
3.0 KiB
ReStructuredText
.. _internals_library:
|
|
|
|
Implementing a Module
|
|
=====================
|
|
|
|
This chapter details how to implement a core module in MicroPython.
|
|
MicroPython modules can be one of the following:
|
|
|
|
- Built-in module: A general module that is be part of the MicroPython repository.
|
|
- User module: A module that is useful for your specific project that you maintain
|
|
in your own repository or private codebase.
|
|
- Dynamic module: A module that can be deployed and imported at runtime to your device.
|
|
|
|
A module in MicroPython can be implemented in one of the following locations:
|
|
|
|
- py/: A core library that mirrors core CPython functionality.
|
|
- extmod/: A CPython or MicroPython-specific module that is shared across multiple ports.
|
|
- ports/<port>/: A port-specific module.
|
|
|
|
.. note::
|
|
This chapter describes modules implemented in ``py/`` or core modules.
|
|
See :ref:`extendingmicropython` for details on implementing an external module.
|
|
For details on port-specific modules, see :ref:`porting_to_a_board`.
|
|
|
|
Implementing a core module
|
|
--------------------------
|
|
|
|
Like CPython, MicroPython has core builtin modules that can be accessed through import statements.
|
|
An example is the ``gc`` module discussed in :ref:`memorymanagement`.
|
|
|
|
.. code-block:: bash
|
|
|
|
>>> import gc
|
|
>>> gc.enable()
|
|
>>>
|
|
|
|
MicroPython has several other builtin standard/core modules like ``io``, ``array`` etc.
|
|
Adding a new core module involves several modifications.
|
|
|
|
First, create the ``C`` file in the ``py/`` directory. In this example we are adding a
|
|
hypothetical new module ``subsystem`` in the file ``modsubsystem.c``:
|
|
|
|
.. code-block:: c
|
|
|
|
#include "py/builtin.h"
|
|
#include "py/runtime.h"
|
|
|
|
#if MICROPY_PY_SUBSYSTEM
|
|
|
|
// info()
|
|
static mp_obj_t py_subsystem_info(void) {
|
|
return MP_OBJ_NEW_SMALL_INT(42);
|
|
}
|
|
MP_DEFINE_CONST_FUN_OBJ_0(subsystem_info_obj, py_subsystem_info);
|
|
|
|
static const mp_rom_map_elem_t mp_module_subsystem_globals_table[] = {
|
|
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_subsystem) },
|
|
{ MP_ROM_QSTR(MP_QSTR_info), MP_ROM_PTR(&subsystem_info_obj) },
|
|
};
|
|
static MP_DEFINE_CONST_DICT(mp_module_subsystem_globals, mp_module_subsystem_globals_table);
|
|
|
|
const mp_obj_module_t mp_module_subsystem = {
|
|
.base = { &mp_type_module },
|
|
.globals = (mp_obj_dict_t *)&mp_module_subsystem_globals,
|
|
};
|
|
|
|
MP_REGISTER_MODULE(MP_QSTR_subsystem, mp_module_subsystem);
|
|
|
|
#endif
|
|
|
|
The implementation includes a definition of all functions related to the module and adds the
|
|
functions to the module's global table in ``mp_module_subsystem_globals_table``. It also
|
|
creates the module object with ``mp_module_subsystem``. The module is then registered with
|
|
the wider system via the ``MP_REGISTER_MODULE`` macro.
|
|
|
|
After building and running the modified MicroPython, the module should now be importable:
|
|
|
|
.. code-block:: bash
|
|
|
|
>>> import subsystem
|
|
>>> subsystem.info()
|
|
42
|
|
>>>
|
|
|
|
Our ``info()`` function currently returns just a single number but can be extended
|
|
to do anything. Similarly, more functions can be added to this new module.
|