Hi Mike,
Thank you so much for your help,
I found out why Ch341a did not work. It is outputting 5 V, when I replaced that with 3.3 V from Raspberry pi, everything works. Raspberry pi is a good flashing tool.
Then I have seabios working. I am total new to Seabios, when I put in a USB key and a SATA hard-drive, it always picks SATA hard-drive. When I press delete key, there is no option to move to USB key.
I am not sure how to use seabios to boot with USB storage.
Thanks,