Asset Intertech has a blog series on debugging Minnowboard firmware using their debugger product. Even if you can’t afford their product, you can still learn about debugging UEFI firmware from this post. 🙂

The Minnowboard Chronicles – Episode 3

As I continue the journey to learn about the internals of UEFI and to debug it with SourcePoint, I encounter some issues doing the firmware build. Last week, I played around with the UEFI shell, and then updated the firmware on my Minnowboard to the latest release (v0.94). Then, I used SourcePoint to look at disassembled code when the platform was sitting in the UEFI shell, waiting for keyboard input. From last time, we can see a number of “INT 3” instructions, with opcode CC. […]

http://blog.asset-intertech.com/test_data_out/2017/01/sourcepoint-debugging-the-minnowboard-turbot.html

http://blog.asset-intertech.com/test_data_out/2017/01/the-minnowboard-chronicles-episode-2.html

http://blog.asset-intertech.com/test_data_out/2017/01/the-minnowboard-chronicles-episode-3.html