I can vouch for this book. A really good introduction to RISC-V is designed, and why it is the way it is, by the original authors. It left me with a very posi

I can vouch for this book. A really good introduction to RISC-V is designed, and why it is the way it is, by the original authors. It left me with a very positive view of RISC-V, as well as reasonable knowledge of the ISA and ABI, which has since proven useful while writing/debugging assembly on the architecture.