The firmware-check feature has been removed as of Oracle Solaris 11.3 SRU 10 (release version later than 220.127.116.11.0).
If you have installed Oracle Solaris 11.3 SRU 10 (version 18.104.22.168.0), there is an Oracle Hardware Management Pack command called firmware-check included that is not supported for Oracle Solaris 11.3. If Oracle Solaris 11.3 SRU 10 (version 22.214.171.124.0) is installed, the svc:/system/management/firmware-check:default service that performs a firmware check at system startup will exit and generate a fault in FMA. This fault will not affect system applications and the service itself will stop running and go into maintenance mode. As the firmware-check service is not supported in this version of the operating system, the service can be permanently disabled.
In addition, attempting to manually run the firmware-check command will generate a "command not supported" error.