Please refer to vendor_hw for more details on rationale of vendoring external repositories.
The RISC-V Compliance Suite defines a series of tests that to ensure the RISC-V system is complies with the RISC-V specification. Normally such a test would be run at the core level instead of the system level, but doing so confers advantages to ensure system integration did not alter the original properties of the core (for example breaking byte or half-word accesses).
To vendor in RISC-V Compliance Suite, please use the commands below.
./util/vendor_hw.py sw/vendor/riscv_compliance.vendor.hjson --verbose