To fix the back button function on a Minix A2 & A2 Lite controller:

Source:
http://www.minixforum.com/threads/fix-a2-a2-lite-back-button-in-xbmc.3294/

More info:
http://kodi.wiki/view/Keymap

Description:
Here is a keymap xml for the A2 & A2 Lite that fixes the back button taking you back to the home screen instead of just one folder up.
You need to copy it to your keymaps folder in:
Android/data/hk.minix.xbmc/files/.xbmc/userdata/keymaps
Reboot XBMC and you should now be able to browse normally.


File = 'keymap.xml'
<keymap>
<global>
<keyboard>
<backspace>Back</backspace>
<key id='61467'>Back</key>
</keyboard>
</global>
<FullscreenVideo>
<keyboard>
<backspace>Back</backspace>
</keyboard>
</FullscreenVideo>
</keymap>


Keymap changed to make both video playback continue playback when you press back and the one step back when you press back