This commit adds full support to the unix port for Bluetooth using the
common extmod/modbluetooth Python bindings. This uses the libusb HCI
transport, which supports many common USB BT adaptors.
https://www.python.org/dev/peps/pep-0475/
This implements something similar to PEP 475 on the unix port, and for the
VfsPosix class.
There are a few differences from the CPython implementation:
- Since we call mp_handle_pending() between any ENITR's, additional
functions could be called if MICROPY_ENABLE_SCHEDULER is enabled, not
just signal handlers.
- CPython only handles signal on the main thread, so other threads will
raise InterruptedError instead of retrying. On MicroPython,
mp_handle_pending() will currently raise exceptions on any thread.
A new macro MP_HAL_RETRY_SYSCALL is introduced to reduce duplicated code
and ensure that all instances behave the same. This will also allow other
ports that use POSIX-like system calls (and use, eg, VfsPosix) to provide
their own implementation if needed.
If the built-in input() is enabled (which it is by default) then it needs
some form of readline, so supply it with one when MICROPY_USE_READLINE=0.
Fixes issue #5658.
This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.
