Thanks for your interest! I'm an author of this book. This book is very beginning as you mentioned and I'm still working on it.

I already succeeded to run xv6 in my RISC-V emulator and wrote a blog post "Made a RISC-V Emulator Running Xv6": https://d0iasm.github.io/blog/risc-v/2020/04/03/xv6-on-my-ri...

I have 2 different RISC-V emulators and its goals are different:

rvemu (https://github.com/d0iasm/rvemu): Can run xv6. It's trying to support Linux and make it faster in the future.

rvemu-for-book (https://github.com/d0iasm/rvemu-for-book): Reference implementation for the book. Simpler than original one.