# sudo apt-get install build-essential git subversion libncurses5-dev
# cd ~
get the latest secn_2.1 branch of vt-firmware.
# mkdir Git
# cd Git
# git clone https://github.com/villagetelco/vt-firmware.git
# cd vt-firmware
# git checkout secn_2.1
# cd Setup-scripts
# ./Setup-AA-r42647-FXS.sh <new-vt-build-directory>
# cp ../Build-scripts/Build-MP02-FXS.sh <new-vt-build-directory>
# cd <new-vt-build-directory>
Edit Build-MP02-FXS.sh to ensure that line 4 points to your Git directory
# ./Build-MP02-FXS.sh