RTEMS - Deploying an Example IOC#

Warning

This tutorial is out of date and will be updated by Nov 2024.

The previous tutorials walked through how to create a Generic linux soft IOC and how to deploy an IOC instance using that Generic IOC.

epics-containers also supports RTEMS 5 running on MVVME5500. We will now will look at the differences for this architecture. Further architectures will be supported in future.

Each beamline or accelerator domain will require a server for serving the IOC binaries and instance files to the RTEMS devices. This needs to be set up for your test beamline before proceeding, see RTEMS - Creating a File Server.

Once you have the file server set up, deploying an IOC instance that uses an RTEMS Generic IOC is very similar to Deploying and Managing IOC Instances.

We will be adding a new IOC instance to the bl01t beamline that we created in the previous tutorials. You will need to have worked through the previous tutorials in order to complete this one.

Preparing the RTEMS Boot loader#

To try this tutorial you will need a VME crate with an MVVME5500 processor card installed. You will also need access to the serial console over ethernet using a terminal server or similar.

Note

DLS Users for details of setting up RTEMS on your VME crates see this internal link

The following crate is already running RTEMS and can be used for this tutorial, but check with the accelerator controls team before using it:

console:: ts0001 7007
crate monitor:: ts0001 7008

It is likely already set up as per the example below.

Use telnet to connect to the console of your target IOC. e.g. telnet ts0001 7007. We want to get to the MOTLoad prompt which should look like MVME5500>. If you see an IOC Shell prompt instead hit Ctrl-D to exit and then Esc when you see Boot Script - Press <ESC> to Bypass, <SPC> to Continue

Now you want to set the boot script to load the IOC binary from the network via TFTP and mount the instance files from the network via NFS. The command gevShow will show you the current state of the global environment variables. e.g.

MVME5500> gevShow
mot-/dev/enet0-cipa=172.23.250.15
mot-/dev/enet0-snma=255.255.240.0
mot-/dev/enet0-gipa=172.23.240.254
mot-boot-device=/dev/em1
rtems-client-name=bl01t-ea-test-02
epics-script=172.23.168.203:/iocs:bl01t/bl01t-ea-test-02/config/st.cmd
mot-script-boot
dla=malloc 0x230000
tftpGet -d/dev/enet1 -fbl01t/bl01t-ea-test-02/bin/RTEMS-beatnik/ioc.boot -m255.255.240.0 -g172.23.240.254 -s172.23.168.203 -c172.23.250.15 -adla
go -a0095F000

Total Number of GE Variables =7, Bytes Utilized =427, Bytes Free =3165

Now use gevEdit to change the global variables to the values you need. For this tutorial we will create an IOC called bl01t-ea-test-02 and for the example we assume the file server is on 172.23.168.203. For the details of setting up these parameters see your site documentation but the important values to change for this tutorial IOC would be:

rtems-client-name:: bl01t-ea-test-02
epics-script:: 172.23.168.203:/iocs:bl01t/bl01t-ea-test-02/config/st.cmd
mot-script-boot (2nd line):: tftpGet -d/dev/enet1 -fbl01t/bl01t-ea-test-02/bin/RTEMS-beatnik/ioc.boot -m255.255.240.0 -g172.23.240.254 -s172.23.168.203 -c172.23.250.15 -adla

Now your gevShow should look similar to the example above.

Meaning of the parameters:

rtems-client-name:: a name for the IOC crate
epics-script:: an NFS address for the IOC’s root folder
mot-script-boot:: a TFTP address for the IOC’s binary boot file

Note that the IP parameters to the tftpGet command are respectively: net mask, gateway, server address, client address.

Creating an RTEMS IOC Instance#

We will be adding a new IOC instance to the bl01t beamline that we created in Create a Beamline Repository. The first step is to make a copy of our existing IOC instance and make some modifications to it. We will call this new IOC instance bl01t-ea-test-02.

cd bl01t
cp -r services/bl01t-ea-test-01 services/bl01t-ea-test-02
# don't need this file for the new IOC
rm services/bl01t-ea-test-02/config/extra.db

We are going to make a very basic IOC with some hand coded database with a couple of simple records. Therefore the Generic IOC that we use can just be ioc-template.

Generic IOCs have multiple targets, they always have a developer target which is used for building and debugging the Generic IOC and a runtime target which is lightweight and usually used when running the IOC in the cluster. The matrix of targets also includes an architecture dimension, at present the ioc-template supports two architectures, linux and rtems, thus there are 4 targets in total as follows:

ghcr.io/epics-containers/ioc-templateruntime
ghcr.io/epics-containers/ioc-templatedeveloper
ghcr.io/epics-containers/ioc-template-rtems-runtime
ghcr.io/epics-containers/ioc-template-rtems-developer

We want to run the RTEMS runtime target on the cluster so this will appear at the top of the values.yaml file. In addition there are a number of environment variables required for the RTEMS target that we also specify in values.yaml. Edit the file services/bl01t-ea-test-02/values.yaml to look like this:

base_image: ghcr.io/epics-containers/ioc-template-rtems-runtime:23.4.2

env:
# This is used to set EPICS_IOC_ADDR_LIST in the liveness probe client
# It is only needed if auto addr list discovery would fail
- name: K8S_IOC_ADDRESS
    value: 172.23.250.15

# RTEMS console connection details
- name: RTEMS_VME_CONSOLE_ADDR
    value: ts0001.cs.diamond.ac.uk
- name: RTEMS_VME_CONSOLE_PORT
    value: "7007"
- name: RTEMS_VME_AUTO_REBOOT
    value: true
- name: RTEMS_VME_AUTO_PAUSE
    value: true

If you are not at DLS you will need to change the above to match the parameters of your RTEMS Crate. The environment variables are:

RTEMS Environment Variables#
Variable	Description
K8S_IOC_ADDRESS	The IP address of the IOC (mot-/dev/enet0-cipa above)
RTEMS_VME_CONSOLE_ADDR	Address of terminal server for console access
RTEMS_VME_CONSOLE_PORT	Port of terminal server for console access
RTEMS_VME_AUTO_REBOOT	true to reboot the hard IOC when the IOC container changes
RTEMS_VME_AUTO_PAUSE	true to pause/unpause when the IOC container stops/starts

Edit the file services/bl01t-ea-test-02/Chart.yaml and change the 1st 4 lines to represent this new IOC (the rest of the file is boilerplate):

apiVersion: v2
name: bl01t-ea-test-02
description: |
    example RTEMS IOC for bl01t

For configuration we will create a simple database with a few records and a basic startup script. Add the following files to the services/bl01t-ea-test-02/config directory.

bl01t-ea-test-02.db#

record(calc, "bl01t-ea-test-02:SUM") {
    field(DESC, "Sum A and B")
    field(CALC, "A+B")
    field(SCAN, ".1 second")
    field(INPA, "bl01t-ea-test-02:A")
    field(INPB, "bl01t-ea-test-02:B")
}

record(ao, "bl01t-ea-test-02:A") {
    field(DESC, "A voltage")
    field(EGU,  "Volts")
    field(VAL,  "0.0")
}

record(ao, "bl01t-ea-test-02:B") {
    field(DESC, "B voltage")
    field(EGU,  "Volts")
    field(VAL,  "0.0")
}

st.cmd#

# RTEMS Test IOC bl01t-ea-test-02

dbLoadDatabase "/services/bl01t/bl01t-ea-test-02/dbd/ioc.dbd"
ioc_registerRecordDeviceDriver(pdbbase)

# db files from the support modules are all held in this folder
epicsEnvSet(EPICS_DB_INCLUDE_PATH, "/services/bl01t/bl01t-ea-test-02/support/db")

# load our hand crafted database
dbLoadRecords("/services/bl01t/bl01t-ea-test-02/config/bl01t-ea-test-02.db")
# also make Database records for DEVIOCSTATS
dbLoadRecords(iocAdminSoft.db, "IOC=bl01t-ea-test-02")
dbLoadRecords(iocAdminScanMon.db, "IOC=bl01t-ea-test-02")

iocInit

You now have a new helm chart in services/bl01t-ea-test-02 that describes an IOC instance for your RTEMS device. Recall that this is not literally where the IOC runs, it deploys a kubernetes pod that manages the RTEMS IOC. It does contain the IOC’s configuration and the IOC’s binary code, which it will copy to the file-server on startup.

Finally you will need to tell the IOC to mount the Persistent Volume Claim that the bl01t-ioc-files service is serving over NFS and TFTP. To do this add the following lines to services/bl01t-ea-test-02/values.yaml:

# for RTEMS IOCS this is the PVC name for the filesystem where RTEMS
# IOCs look for their files - enable this in RTEMS IOCs only
nfsv2TftpClaim: bl01t-ioc-files-claim

You are now ready to deploy the IOC instance to the cluster and test it out.

Deploying an RTEMS IOC Instance#

To deploy an IOC instance to the cluster you can use one of two approaches:

push your beamline repo to GitHub and tag it. Then use ec deploy to deploy the resulting versioned IOC instance. This was covered for linux IOCs in Deploying and Managing IOC Instances.
use ec deploy-local to directly deploy the local copy of the IOC instance helm chart to kubernetes as a beta version. This was covered for linux IOCs in –local_deploy_ioc–.

Both types of deployment of IOC instances above work exactly the same for linux and RTEMS IOCs. We will do the latter as it is quicker for the purposes of the tutorial.

Execute the following commands:

cd bl01t
ec deploy-local services/bl01t-ea-test-02

When an RTEMS Kubernetes pod runs up it will make a telnet connection to the hard IOC’s console and present the console as stdin/stdout of the container. This means once you have done the above deployment the command:

ec logs bl01t-ea-test-02 -f

will show the RTEMS console output, and follow it along (-f) as the IOC starts up. You can hit ^C to stop following the logs.

You can also attach to the container and interact with the RTEMS console via the telnet connection with:

ec attach bl01t-ea-test-02

Most likely for the first deploy your IOC will still be sitting at the MVME5500> prompt. If you see this prompt when you attach then you need to type reset to restart the boot-loader. This should then go through the boot-loader startup and eventually start the IOC.

Checking your RTEMS IOC#

To verify that your RTEMS IOC is working you should be able to execute the following commands and get correct sum of the A and B values:

caput bl01t-ea-test-02:A 12
caput get bl01t-ea-test-02:B 13
caget get bl01t-ea-test-02:SUM