There is some work on an OS-agnostic feature detection C API: https://github.com/riscv-non-isa/riscv-c-api-doc/blob/main/src/c-api.adoc#extension-bitmask https:

There is some work on an OS-agnostic feature detection C API: https://github.com/riscv-non-isa/riscv-c-api-doc/blob/main/src/c-api.adoc#extension-bitmask https://github.com/riscv-non-isa/riscv-c-api-doc/blob/main/s.... Still quite new though, and potentially might change (as it did a month ago).