Update CI docs to include documentation of the runner VM

ci/README.md

@@ -10,3 +10,33 @@ It runs [make](quad/Makefile) under the quad directory to build the project.
 ## Test Stage
 The test stage is defined by the [`ci-test.sh`](ci/ci-test.sh) file.
 It runs [make test](quad/Makefile#L36) under the quad directory to run the tests.
+
+# CI Server
+The CI server for this project is at `microcart.ece.iastate.edu`
+login information should be handed off outside this repo for security reasons.
+The gitlab runner uses docker to launch a container, in which the scripts are run.
+The VM is running Red Hat Enterprise Linux, which as of Oct. 6, 2018 was licensed.
+**Note:** RHEL uses `yum` for package management, but the docker image uses `apt-get`.
+
+## Accessing System Folders
+If you need to access any folders on the VM from within the docker,
+the information [here](https://docs.gitlab.com/runner/configuration/advanced-configuration.html#volumes-in-the-runners-docker-section) should help
+Specifically this part:
+
+### Example 2: mount a host directory as a data volume
+In addition to creating a volume using you can also mount a directory from your
+Docker daemon's host into a container. It's useful when you want to store builds
+outside the container.
+
+    [runners.docker]
+      ... whatever config is already there ...
+      volumes = ["/path/to/persistent/data/in/container", /path/to/bind/from/host:/path/to/bind/in/container:rw"]
+
+## Accessing a remote share on the VM
+To get to the Xilinx tools for hardware simulation, we need access to
+`logic.ece.iastate.edu/export/Xilinx` as a mounted folder. This can be done with NFS.
+NFS is installed and the folder mounted. If it becomes unmounted, then run 
+
+    $ sudo mount logic.ece.iastate.edu:/export/Xilinx /remote/Xilinx
+
+on the VM. This may not be doable from within the CI run as it is in a container (Docker image) that may behave differently or have different permissions.