doc: Add environemt variable overriding to get started

This comit adds details about the overriding of environment variables such as
ESPPORT and ESPBAUD to the get started guide.

diff --git a/docs/en/get-started/index.rst b/docs/en/get-started/index.rst
index 02a302dd0fc4bd0e0ad2be8dd86627169fd9b9bb..c558dbf38a2ec3ae9026451ddfbdd52a6995b8a3 100644 (file)
--- a/docs/en/get-started/index.rst
+++ b/docs/en/get-started/index.rst
@@ -315,6 +315,33 @@ That's all what you need to get started with ESP32!
 Now you are ready to try some other :idf:`examples`, or go right to developing your own applications.\r
 \r
 \r
+Environment Variables\r
+=====================\r
+\r
+Some environment variables can be specified whilst calling ``make`` allowing users to **override arguments without needing to reconfigure them using** ``make menuconfig``.\r
+\r
++-----------------+--------------------------------------------------------------+\r
+| Variables       | Description & Usage                                          |\r
++=================+==============================================================+\r
+| ``ESPPORT``     | Overrides the serial port used in ``flash`` and ``monitor``. |\r
+|                 |                                                              |\r
+|                 | Examples: ``make flash ESPPORT=/dev/tty/USB0``,              |\r
+|                 | ``make monitor ESPPORT=COM1``                                |\r
++-----------------+--------------------------------------------------------------+\r
+| ``ESPBAUD``     | Overrides the serial baud rate when flashing the ESP32.      |\r
+|                 |                                                              |\r
+|                 | Example: ``make flash ESPBAUD=9600``                         |\r
++-----------------+--------------------------------------------------------------+\r
+| ``MONITORBAUD`` | Overrides the serial baud rate used when monitoring.         |\r
+|                 |                                                              |\r
+|                 | Example: ``make monitor MONITORBAUD=9600``                   |\r
++-----------------+--------------------------------------------------------------+\r
+\r
+.. note::\r
+    Users can export environment variables (e.g. ``export ESPPORT=/dev/tty/USB0``).\r
+    All subsequent calls of ``make`` within the same terminal session will use \r
+    the exported value given that the variable is not simultaneously overridden.\r
+\r
 Updating ESP-IDF\r
 ================\r
 \r