How should that work without an OS available to the board?
And why don't you recommend to simply read the two chapters 'first steps' and 'troubleshooting' in the product's user manual?
Because noone would expect the user manual to be hidden inside a Google Drive link somewhere (but that's easy, you just have to read through all forum posts made by 'sinovoip' to find such basic stuff) instead of being linked to from the product page? Or because the 'user manual' is mostly copy&paste from other SinoVoip 'user manuals' and the 'informations' therein are questionable?
The good news: they updated some wrong informations in the M3's user manual. The bad news: the version remained "V1.0" so anyone searching for most recent informations is lost as usual.
And still so many informations are missing (is there something on eMMC or not when the M3 leaves the factory? It's not even mentioned that you can also boot from eMMC but 'SD-card is optional'! How to flash an image to eMMC? 'First Steps'? 'Troubleshooting chapter'?) or are still wrong (eg. no need to use SDFormatter in Windows or use fdisk/mkfs.vfat in Linux, that's moronic copy&paste from somewhere else)
Wouldn't it be nice to provide flashing installations together with a download link for an Android image if it's necessary to use 'Phoenix Card' (this is the download link from within the user manual -- broken link as expected) and you can't use Win32 Diskimager? Of course, but they neither care nor will anybody find this Google Drive link since it's just another useless forum post from 'sinovoip'.
It's so funny that these guys didn't learn a single lesson. They simply don't care about anything else than hardware even if that means that this hardware only can be used as a paperweight