The Root CA certificate (DESRCACC100001) is not exposed at the interface. It’s just stored internally during production and can be used to verify Device Issuer CA certificates.
You could extract the Device Issuer certificate from your device and pass that to the (same or other) device in the PSO:VERIFY CERTIFICATE command. The SmartCard-HSM would then validate the Device Issuer certificate and make it’s public key internally available. In a subsequent step you could use your device certificate and have that validated with the same command. Ultimately the SmartCard-HSM would trust a public key generated on a different device, based on the full chain of certificates from the public key to the SRCA (Remember, freshly generated key pairs get their public key signed by the device authentication key (in TR-03110 CSR format). Via the chain CSR, Device Certificate, Device Issuer CA Certificate, Scheme Root CA Certificate you can prove authenticity of a key pair generated on a SmartCard-HSM. That mechanism is for example used in the PKI-as-a-Service Portal to authenticate public keys when CDN certificates are issued.
A good example that shows the process is available in the agreeKey.js example available at the CDN. In that example two EC keys are generated and their authenticity is validated by a peer SmartCard-HSM in order to agree a common secret. The mechanism has been developed in a customer project to agree shared keys in an encrypted communication using SRTP. Both peers in that setup authenticate each other based on CV-certificate exchanged during communication setup.