I have so many questions:
- Where can I get the ISA specification?[1]
- Where can I get a compiler?
- Is there a link to the "softcore model"?
With RISC-V you can start very simple and small (micro-controller) and work your way up in understanding and implementation to a very large core (application class). POWER is a monster of an architecture, designed more for "big iron". I guess that might limit the "hobbyist" factor RISC-V has.
1. This I think, all 1200 pages of it: https://openpowerfoundation.org/?resource_lib=power-isa-vers...
The toy soft-core VHDL model that is referred to there will be available at https://github.com/antonblanchard/microwatt at some point in the next couple of days.