cosmok82 has posted a tutorial on how to unbrick a Teclast X98 BIOS with Bus Pirate 4 and Flashrom:
Sometimes you put your feet out of bed and a bad day comes. In all these days C/D is close to you! Enjoy our guide, step by step to unbrick your Teclast X98 tablet.
First of all.
Be very careful, you can damage your tablet if you make an hardware variation or a version of BIOS not in conformity with your tablet model. I take absolutely no responsibility in both cases. If you haven’t the right know-how to make the circuit by yourself, you have to ask help to a technician!
This is the first guide to unbrick this particular BIOS with Bus Pirate 4 around the world. It was designed for BP4’s header connection, for the version 3.6 of Bus Pirate the situation with the connections is a bit different, take care!
More details at CreativitySlashDesign blog.
Via the forum.
You can get a Bus Pirate v4 for $40, including worldwide shipping.