Add tcp-serial-redirect target and add WSL notes on debugging

Don't kill terminal when running gdb, it'll kill tcp redirector

Sming/project.mk

@@ -486,7 +486,7 @@ cs-dev: ##Apply coding style to all files changed from current upstream develop
 	$(SMING_MAKE) $@
 
 .PHONY: gdb
-gdb: kill_term ##Run the debugger console
+gdb: ##Run the debugger console
 	$(GDB_CMDLINE)
 
 .PHONY: fetch
@@ -544,6 +544,18 @@ otaserver: all ##Launch a simple python HTTP server for testing OTA updates
 	$(info Starting OTA server for TESTING)
 	$(Q) cd $(FW_BASE) && $(PYTHON) -m SimpleHTTPServer $(SERVER_OTA_PORT)
 
+
+#
+.PHONY: tcp-serial-redirect
+tcp-serial-redirect: ##Redirect COM port to TCP port
+	$(info Starting serial redirector)
+ifdef WSL_ROOT
+	$(Q) cmd.exe /c start /MIN python3 $(WSL_ROOT)/$(SMING_HOME)/../Tools/tcp_serial_redirect.py $(COM_PORT) $(COM_SPEED_SERIAL)
+else
+	$(Q) gnome-terminal -- bash -c "$(PYTHON) $(SMING_HOME)/../Tools/tcp_serial_redirect.py $(COM_PORT) $(COM_SPEED_SERIAL)"
+endif
+
+
 ##@Help
 
 .PHONY: list-config

docs/source/getting-started/windows/wsl.rst

@@ -94,6 +94,30 @@ For example::
    make flash COM_PORT=COM4
 
 
+Serial debugging
+----------------
+
+Again, as we have no direct access to USB COM ports a workaround is required.
+A small python application can be run on Windows to act as a simple bridge between the serial port and a TCP port.
+See ``Tools/tcp_serial_redirect.py`` - run without arguments to see available options.
+
+You can start the server like this::
+
+   make tcp-serial-redirect
+
+A new console will be created (minimised) showing something like this::
+
+   --- TCP/IP to Serial redirect on COM4  115200,8,N,1 ---
+   --- type Ctrl-C / BREAK to quit
+   Waiting for connection on 192.168.1.101:7780...
+
+This uses the current :envvar:`COM_PORT` and :envvar:`COM_SPEED_SERIAL` settings.
+
+Now we can start the debugger::
+
+   make gdb COM_PORT_GDB=192.168.1.101:7780
+
+
 Valgrind
 --------