Add env var SMING_TOOLCHAINS to allow easier change of toolchains ins…

…tallation folder (#2894)

Tools/export.sh

@@ -38,15 +38,18 @@ fi
 
 export PYTHON=${PYTHON:=$(which python3)}
 
+# Toolchain paths
+export SMING_TOOLCHAINS=${SMING_TOOLCHAINS:=/opt}
+
 # Esp8266
-export ESP_HOME=${ESP_HOME:=/opt/esp-quick-toolchain}
+export ESP_HOME=${ESP_HOME:=$SMING_TOOLCHAINS/esp-quick-toolchain}
 
 # Esp32
-export IDF_PATH=${IDF_PATH:=/opt/esp-idf}
-export IDF_TOOLS_PATH=${IDF_TOOLS_PATH:=/opt/esp32}
+export IDF_PATH=${IDF_PATH:=$SMING_TOOLCHAINS/esp-idf}
+export IDF_TOOLS_PATH=${IDF_TOOLS_PATH:=$SMING_TOOLCHAINS/esp32}
 
 # Rp2040
-export PICO_TOOLCHAIN_PATH=${PICO_TOOLCHAIN_PATH:=/opt/rp2040}
+export PICO_TOOLCHAIN_PATH=${PICO_TOOLCHAIN_PATH:=$SMING_TOOLCHAINS/rp2040}
 
 # Provide non-apple CLANG (e.g. for rbpf library)
 if [ -n "$GITHUB_ACTIONS" ] && [ "$(uname)" = "Darwin" ]; then

docs/source/getting-started/config.rst

@@ -11,11 +11,21 @@ and integrated development environments (IDEs) work correctly.
 
 You can find a list of these in :source:`Tools/export.sh`.
 
-For Linux and WSL2, append values to your ``~/.bashrc`` file::
+For Linux and WSL2, append :envvar:`SMING_HOME` to your ``~/.bashrc`` file::
 
    # All architectures
    export SMING_HOME=/opt/sming/Sming
-
+   
+:envvar:`SMING_HOME` is the only mandatory environmental variable.
+
+If you want to change the location where the toolchain will be downloaded and installed you can append the values below::
+	
+   # Specifies a common toolchains directory
+   export SMING_TOOLCHAINS=/opt
+   
+The :envvar:`SMING_TOOLCHAINS` is optional. As are the ones below. You can append them to your ``~/.bashrc`` file only
+if you need to change the location of the installed toolchains::
+  
    # Esp8266
    export ESP_HOME=/opt/esp-quick-toolchain