Author here. aarch64 is something I haven't looked into yet. Last time I tried, I was able to boot to userspace on a VisionFive2 (riscv64gc), but it's been a while and the port has likely bit-rotted. It's missing a lot of platform drivers since there is no ACPI firmware on those devices. There is no audio yet, but I do plan on porting Pulse with OSS drivers in the future. Regarding USB, I have a local change set with HID on xHCI, but no Mass Storage support.