Don't change this directory nor content of it.
This serves as image for fail-safe alternate booting.
Alternate boot can be invoked by pressing hw button on UniPi Patron PLC or G1 gateway
 during power-on.

Alt-boot configures network system:
- Ethernet port is configured as dhcp-client and 
- Ethernet port has also fixed address 192.168.200.200
- On port 80 there is running web server for image update 
- On port 88 there is running web server with javascript  terminal emulator
