Using the NODEMCU_ namespace prefix makes it obvious that these are not
part of Lua proper (contrast, e.g., LUA_BUILTIN_STRING). Using
"CMODULE" gives us room to differentiate between modules whose
implementation is in C and whose implemenation is in Lua ("LMODULE").
The ESP8266 branch can adopt the same convention when it moves to
Kconfig; see https://github.com/nodemcu/nodemcu-firmware/issues/3130
RTOS driver evicted as it did not play nice with stdio etc.
Implemented a minimal driver to fully support Lua console on UART0. Output
on UART0 done via stdout (provided by the IDF). Input and setup handled
via driver_console/console.c. In addition to the direct input function
console_getc(), the driver also registers in the syscall tables to enable
regular stdio input functions to work (yay!). The Lua VM is still using the
direct interface since it's less overhead, but does also work when going
through stdin/fd 0.
Auto-bauding on the console is not yet functional; revisit when the UART docs
are available.
Module registration/linking/enabling moved over to be Kconfig based. See
updates to base_nodemcu/include/module.h and base_nodemcu/Kconfig for
details.
The sdk-overrides directory/approach is no longer used. The IDF is simply
too different to the old RTOS SDK - we need to adapt our code directly instead.
Everything in app/ is now unused, and will need to be gradually migrated
into components/ though it is probably better to migrate straight from the
latest dev branch.