A Portable and Linux Capable RISC-V Computer System in Verilog HDL | Junya Miura, Hiromu Miyazaki and Kenji Kise, Cornell University

RISC-V is an open and royalty free instruction set architecture which has been developed at the University of California, Berkeley. The processors using RISC-V can be designed and released freely. Because of this, various processor cores and system on chips (SoCs) have been released so far. However, there are a few public RISC-V computer systems that are portable and can boot Linux operating systems
paper: https://arxiv.org/pdf/2002.03576.pdf