[ICF-1700] How to use the Firmware Upgrade

Please follow the step to upgrade the firmware as below

1. Create a directory named implinux in the USB disk, and copy the update file to this directory, and then insert the USB into the phone.

2. Phone reboot will automatically compare the update version number in the USB disc and telephone own version number, if not the same version and higher than the existing version, the phone will automatically upgrade. (Upgrade all system).