In 2022 I ported my MIPS book to RISC-V. Like the original MIPS version it’s targeted at college students in the standard RISC-V/architecture type course (often using the Patterson and Hennessy textbook). Despite that, anyone can use it, though basic knowledge of C syntax helps.
The book is free, but any level of support gets you the solutions to the chapter exercises. If you already have the MIPS exercises, these are the same, just ported to RISC-V to run on RARS so unless you really want to show your support you don’t really need them since MIPS and RISC-V are at least 80% the same.
All higher levels of support get their name with an optional link on the Supporters page at the end of the book, while the Corporate Sponsors will also have an image/logo on the dedication page.