Returning a pointer to a buffer from a c extension

[kdschlosser]

I have a user c module that gets compiled with MicroPython. This module handles setting up the busses for displays. Because of the different allocation mechanisms used between the different boards I need to be able to create the frame buffer in C code. The graphics framework is also a user c module. The bus drivers are a separate module than the framework and I would like to keep it that way. One of the things I need to be able to do is collect the frame buffer and pass it over to the framework. This is something that would be done in Python code.

I need to know how I would go about returning an array.array or a bytearray or a bytes object from a function that is defined in the c module. I have not found this being done anywhere in Micropython. Maybe even a memory view object would work. I need a pointer to be passed from C code to the python side of things and then back into C code.

[andrewleech]

I'm pretty sure what you want is

mp_obj_t mp_obj_new_bytearray_by_ref(size_t n, void *items);

micropython/py/obj.h

Line 971 in b5449b0

mp_obj_t mp_obj_new_bytearray_by_ref(size_t n, void *items);

[kdschlosser]

I think you are correct. I will give that a shot and see what happens.