One of the areas being worked on upstream recently for the RISC-V architecture’s Linux kernel support is EFI handling. The preliminary work for supporting EFI on RISC-V is set to land for the Linux 5.8 kernel.
article: https://www.phoronix.com/scan.php?page=news_item&px=RISC-V-EFI-Linux-5.8-Prep