@Zheng-Han Thank you for your reply. Sorry to be a pain but can I specify my previous question?
According to @Larry-Pinney's photo Omega2+ has a Winbond 25Q256FV flash.
Does Omega2S+ also have a Winbond 25Q256FV or some fully equivalent flash chip?
@wdu , hi! Can you share with us the details? Did you just write the binary to the raw flash memory? Starting at which address? I imagine at least some part of the 32MB of flash must be partitioned with a FS (jffs2?), so we must be careful not to overwrite it, right?
Can someone point me to or share the flash's map / partitioning scheme?
First of all, there is no PCI (or PCIe) bus on Omega2, thus no go on that route.
Regarding USB-VGA output dongle:
It needs a driver on the MT7688 side (Omega2 side) and not only that,
it needs a large frame buffer on the Omega2. That USB-VGA dongle is just a data pump/VGA output formatter to continuously refresh/display the content of the frame buffer.
In such case, Omega2 does not have large enough memory, nor enough horse power to isochronously send the FB data out over USB.
In another word: dead-end.
Use the device as what its is most suitable for.
Your case needs a device such as Raspberry Pi zero.