UART REPL support was lost in os.dupterm() refactorings, etc. As
os.dupterm() is there, implement UART REPL support at the high level -
if MICROPY_STDIO_UART is set, make default boot.py contain os.dupterm()
call for a UART. This means that changing MICROPY_STDIO_UART value will
also require erasing flash on a module to force boot.py re-creation.
There is a minor functional change with this patch, that the GPIO are now
configured in fast mode, whereas they were in high speed mode before. But
the SDIO should still work because SD CK frequency is at most 25MHz.
They are the same as the existing raw constants (namely 0, 1, 2) but we
want to explicitly show that one can use the HAL's constants if necessary
(eg the mpconfigboard.h files do use the HAL's constants to define the
pull state of certain configurable pins).
Without this the timer will have random values for its State and Lock
entries. The object can then be in a locked state leading to some HAL
functions returning immediately with an error code (which is unchecked).
This patch fixes such a bug which did manifest itself as PWM not working
correctly for LEDs.
This check always fails (ie chr0 is never EOF) because the callers of this
function never call it past the end of the input stream. And even if they
did it would be harmless because 1) reader.readbyte must continue to
return an EOF char if the stream is exhausted; 2) next_char would just
count the subsequent EOF's as characters worth 1 column.
Damien George
Paul Sokolovsky
sergiuszm