From d2686770174544aaaf4b9642e7f60628b52245c0 Mon Sep 17 00:00:00 2001
From: Darian Leung <darian@espressif.com>
Date: Sun, 2 Sep 2018 21:24:35 +0800
Subject: [PATCH] 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.
---
 docs/en/get-started/index.rst | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/docs/en/get-started/index.rst b/docs/en/get-started/index.rst
index 02a302dd0f..c558dbf38a 100644
--- 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.
 
 
+Environment Variables
+=====================
+
+Some environment variables can be specified whilst calling ``make`` allowing users to **override arguments without needing to reconfigure them using** ``make menuconfig``.
+
++-----------------+--------------------------------------------------------------+
+| Variables       | Description & Usage                                          |
++=================+==============================================================+
+| ``ESPPORT``     | Overrides the serial port used in ``flash`` and ``monitor``. |
+|                 |                                                              |
+|                 | Examples: ``make flash ESPPORT=/dev/tty/USB0``,              |
+|                 | ``make monitor ESPPORT=COM1``                                |
++-----------------+--------------------------------------------------------------+
+| ``ESPBAUD``     | Overrides the serial baud rate when flashing the ESP32.      |
+|                 |                                                              |
+|                 | Example: ``make flash ESPBAUD=9600``                         |
++-----------------+--------------------------------------------------------------+
+| ``MONITORBAUD`` | Overrides the serial baud rate used when monitoring.         |
+|                 |                                                              |
+|                 | Example: ``make monitor MONITORBAUD=9600``                   |
++-----------------+--------------------------------------------------------------+
+
+.. note::
+    Users can export environment variables (e.g. ``export ESPPORT=/dev/tty/USB0``).
+    All subsequent calls of ``make`` within the same terminal session will use 
+    the exported value given that the variable is not simultaneously overridden.
+
 Updating ESP-IDF
 ================