This is the rust implementation of the elf component which drivers are loaded into. It's primary duties are related to managing the driver runtime as well as managing the driver lifecycle.
To add this component to your build, append --with-base src/devices/bin/driver-host to the fx set invocation.
Use ffx component run to launch this component into a restricted realm for development purposes:
$ ffx component run /core/ffx-laboratory:driver-host fuchsia-pkg://fuchsia.com/driver-host#meta/driver-host.cm
Unit tests for driver-host are available in the driver-host-tests package.
$ fx test driver-host-tests