Docs are here: http://tannewt-micropython.readthedocs.io/en/microcontroller/
It differs from upstream's machine in the following ways:
* Python API is identical across ports due to code structure. (Lives in shared-bindings)
* Focuses on abstracting common functionality (AnalogIn) and not representing structure (ADC).
* Documentation lives with code making it easy to ensure they match.
* Pin is split into references (board.D13 and microcontroller.pin.PA17) and functionality (DigitalInOut).
* All nativeio classes claim underlying hardware resources when inited on construction, support Context Managers (aka with statements) and have deinit methods which release the claimed hardware.
* All constructors take pin references rather than peripheral ids. Its up to the implementation to find hardware or throw and exception.
The compiler treats `if (MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE)` as
a normal statement and generates assembly for it in degug mode as if MICROPY_ERROR_REPORTING
is an actual symbol instead of a preprocessor definition.
As such linking fails because mp_arg_error_terse_mismatch is not defined when
MICROPY_ERROR_REPORTING_TERSE is detailed or normal.
Going from MICROPY_ERROR_REPORTING_NORMAL to
MICROPY_ERROR_REPORTING_TERSE now saves 2020 bytes ROM for ARM Thumb2,
and 2200 bytes ROM for 32-bit x86.
This is about a 2.5% code size reduction for bare-arm.
Need to have a policy as to how far we go adding keyword support to
built ins. It's nice to have, and gets better CPython compatibility,
but hurts the micro nature of uPy.
Addresses issue #577.
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
These are to assist in writing native C functions that take positional
and keyword arguments. mp_arg_check_num is for just checking the
number of arguments is correct. mp_arg_parse_all is for parsing
positional and keyword arguments with default values.
