Error: Unable to run mksdcard SDK tool
This really needs to be added to the documentation, which is why I filed an issue about it a few months ago...
You need some 32-bit binaries, and you have a 64-bit OS version (apparently). Try:
sudo apt-get install lib32z1 lib32ncurses5 lib32bz2-1.0 lib32stdc++6
That worked for me on Ubuntu 14.10.
UPDATE 2017-12-16: The details will vary by Linux distro and version. So for example, this answer covers newer Ubuntu versions.
For UBUNTU 15.04,15.10,16.04 LTS, Debian 8 & Debian 9 Try this command:
sudo apt-get install lib32stdc++6