tools/serial.inc.mk: Support miniterm.py.

miniterm.py is a simple terminal program that is included with pyserial.
This means that it is available wherever pyterm can work. It allows raw
access, does line translation and passes through special characters.

For test scripts, a terminal that does not modify the input and output
streams, configured without local echo, is preferred as it ensures the
test setup is introducing as few noise as possible.

makefiles/tools/serial.inc.mk

@@ -19,4 +19,9 @@ ifeq ($(RIOT_TERMINAL),pyterm)
 else ifeq ($(RIOT_TERMINAL),picocom)
   export TERMPROG  ?= picocom
   export TERMFLAGS ?= --nolock --imap lfcrlf --echo --baud "$(BAUD)" "$(PORT)"
+else ifeq ($(RIOT_TERMINAL),miniterm.py)
+  export TERMPROG  ?= miniterm.py
+  # The RIOT shell will still transmit back a CRLF, but at least with --eol LF
+  # we avoid sending two lines on every "enter".
+  export TERMFLAGS ?= --eol LF "$(PORT)" "$(BAUD)"
 endif

tests/shell/Makefile

@@ -12,4 +12,10 @@ BOARD_BLACKLIST += chronos
 
 TEST_ON_CI_WHITELIST += all
 
+# In order to properly test and debug the shell it is better to use a terminal
+# program that does not modify the input and output streams and has no buffering.
+ifneq ($(BOARD), native)
+  RIOT_TERMINAL?=miniterm.py
+endif
+
 include $(RIOTBASE)/Makefile.include