Pleased to announce that we made Alpine Linux boot and work with mainline u-boot, opensbi and linux kernel, with some patches for u-boot and more patches for kernel.
Short guide how to use it is here https://arvanta.net/alpine/u-boot-visionfive2-alpine/
Source files for build u-boot and kernel are here https://gitlab.alpinelinux.org/nmeum/alpine-visionfive/-/tree/main/starfive
And guide how to install Alpine Linux on VisionFive V2 and V1 is here https://arvanta.net/alpine/alpine-on-visionfive/