tools/pyboard.py: Avoid initial blocking read in read_until().

This applies the mpremote commit 0d46e45a1f72ee61a153c41aaaf6c63818ccffb0
to pyboard.py.

If the target does not return any data then `read_until()` will block
indefinitely.  Fix this by making the initial read part of the general read
look, which always checks `inWaiting() > 0` before reading from the serial
device.

Also added the UART timeout to the constructor.  This is not currently used
but may be used as an additional safeguard.

Signed-off-by: Damien George <damien@micropython.org>

0 files changed, 0 insertions, 0 deletions