Through the means of Android firmware upgrade, it is usually being done by applying the pre-downloaded firmware pack from the microSD in the factory firmware upgrade settings or conventionally done by the means of over-the-air (OTA) upgrade. In a recent Huawei announcement, they will be discontinuing software update for EMUI through pre-downloaded firmware zip files and all users will be upgrading through OTA with their smartphones.
This policies commences from 7th September 2017 and software upgrade through microSD is no longer supported. This is to enhance the stability and security of each software upgrade applied to the user’s smartphone.