FRED for PikeOS/ElinOS

This project contains the porting of some parts of the FRED Framework for PikeOS/ElinOS. This project contains all the information needed to build a working system image for the Xilinx Ultrascale+ ZCU102 Evaluation Board containing:

• the PikeOS hypervisor, encapsulating
• an ElinOS (real-time) kernel with FRED Framework support,
• and corresponding test applications.

NOTE: PikeOS/ElinOS are SysGo products.

Prerequisites

You must have a working ElinOS/PikeOS/CODEO installation on your machine and appropriate licenses from SysGo. In the following, we assume that the following software is installed on your system.

Software	Version	Location
ElinOS	7.1	/opt/elinos-7.1
PikeOS	5.1	/opt/pikeos-5.1

In addition, we asume that a valid license server is installed in /usr/lmx-5.1 and can be started via systemctl.

Building

Use the ./build.sh command to build the project from scratch.

You might be prompted for your sudo password, but only to restart the license server. If you make changes in some subprojects, refer to the individual READMEs for how to apply the changes. If changes are minimal, chances are that simply re-runnning build.sh.

NOTE: If a warning about a possibly incorrect project configuration fires up, do not panic. It is expected. Just check the last line of output before the script exits: if it contains the Success! string, then you are all set! 😄

Example:

> ./build.sh
 +-- Restarting the license server
     You might be prompted for your password...
 +-- Running Step 'Fred Library' ...
 +-- Running Step 'Fred Server' ...
 +-- Running Step 'ZCU102 HwVirt PikeOS' ...
! Validation found problems. Generated configuration files may be invalid. Call --validate in non-interactive mode to get more information about the problems.
 +-- Success!

Changing the configuration

You can change some of the build parameters of the project by exporting some environment variables before running the build.sh script.

Most notably, applications can be built in Release or Debug mode by setting the RELEASE_TYPE variable accordingly.

For more info see the following README.md files:

• fred-lib.app/README.md
• fred-server.app/README.md

A summary of the major compilation options follows:

Global variables

Variable	Accepted Values	Default Value
BUILD_TYPE	Release, Debug	Release

Fred Server specific variables

Variable	Accepted Values	Default Value
FREDS_LOG_LEVEL	mute, simple, full, pedantic	mute
FREDS_PATH	Any valid Unix path	/opt/fredsys

Fred Clients (RTDAG) specific variables

Variable	Accepted Values	Default Value
RTDAG_LOG_LEVEL	none, error, warning, info, debug	none
RTDAG_TASK_IMPL	thread, process (untested)	thread
RTDAG_INPUT_TYPE	yaml, header (untested)	yaml
RTDAG_COMPILER_BARRIER	ON, OFF	ON
RTDAG_MEM_ACCESS	ON, OFF	OFF
RTDAG_COUNT_TICK	ON, OFF	ON

Burning an SD Card

To test/use the built system on your Xilinx Ultrascale+ ZCU102 Evaluation Board, you must flash an SD Card with the system and insert it in your device. We assume that you have an SD Card characterized by the following partitions:

Partition	"Mount Point"	Type	Size
Boot	/boot	FAT32	At least 20MB, but more space does not hurt
Root FS	/	EXT2	Remaining SD Card size

NOTE: Before burning the SD Card, beware that all its content WILL be lost.

To burn the SD Card use the ./burn.sh script as follows:

sudo ./burn.sh BOOT_PATH ROOTFS_PATH

The script will ask for confirmation if the two paths exist, like this:

> sudo ./burn.sh /run/media/user/BOOT /run/media/user/ROOT
About to write to the following directories,
please type 'y' to confirm.
Anything else will exit.

boot:     '/run/media/user/BOOT'
rootfs:   '/run/media/user/ROOT'

Are you sure? [y/N] y
 +-- Restarting the license server...
 +-- Setting target directories as instructed...
 +-- Cleaning target directories...
 +-- Burning on target directories...

 [...]

 +-- Success!

Again, the last line is the reference for whether the process was a success or not.

Booting your ZCU102 Evaluation Board

Simply place the SD Card in the right slot and set the hardware switches on the board to boot from SD.

The correct configuration is the following (see Xilinx Reference):

MODE Switch (SW6)	Status
1	OFF
2	ON
3	ON
4	ON

NOTE: The switches are ON when they are pulled DOWN. So basically move UP only the 1st one (following the arrow on the device).

The boot sequence will run automatically and without intervention as soon as you move the POWER Switch (SW1) to the ON position.

To connect to your board using serial, connect a USB cable to the J83 output on the Evaluation Board and then run the following command on your host terminal:

sudo screen /dev/ttyUSB0 115200

NOTE: The number of the TTY might differ on your system.

Starting FRED Server

On first boot, run the following sequence of commands:

cd /opt/fredsys
tar -xf fred.tar.gz

Then the following is the sequence of operations necessary to start the FRED Server on your host on each boot:

modprobe zynqmp-fpga-fmod
modprobe fred-buffctl
load_hw
fred-server &

You can now start FRED Client applications. For example, you can run the sum-vec application:

sum-vec

NOTICE: The FRED Device Tree Overlay does not work. Refer to zcu102_hwvirt_linux.app/README.md for further info.

Acknowledgements

Thanks for Enkhtuvshin Janchivnyambuu and Andrej Kruták from SysGo for the tecnical support during this migration of FRED framework from Petalinux to ElinOS.

Authors

• Alexandre Amory (Feb 2023)
• Gabriele Ara (May 2023)

Real-Time Systems Laboratory (ReTiS Lab), Scuola Superiore Sant'Anna (SSSA), Pisa, Italy.

Funding

This software package has been developed in the context of the AMPERE project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 871669.

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Useful information for debugging purposes

The projects fred-lib.app and fred-server.app were made to enable step-by-step debug of both FRED Client and Server within CODEO using a gdbserver.

Create a Connection

In the Remote Systems window, select Define a connection to remote system. In the New Connection window, select CODEO -> ELinOS and click next.

Then, as shown in the next image, set the static IP, which is configured to 10.30.4.114, add a connection name (in this case conn), and set Product version to ELinOS 7.1, and Read configuration from project to ${workspace_loc:/zcu102_hwvirt_linux.app}.

Debug Configuration

It's necessary to create a Debug Configuration for each ElinOS Application Project, in this case fred-lib.app and fred-server.app. In CODEO, go to menu Run -> Debug Configurations.... Then add two C/C++ ELinOS Remote Applications. The first one called fred-server and the second one called sum-vec. For fred-server, the relevant tabs are shown next.

The sum-vec configuration is very similar. Next is the image of the Main tab. The Connection tab needs to use a different port number, let's say 2345. The Remote Debugging tab is the same as fred-server.

Debugging

Since fred-lib.app and fred-server.app communicate with each other via sockets, the order and the location of the breakpoints matter. For example, a breakpoint in a part of a code that blocks a transaction (fred_init, fred_bind, and fred_map_buff, fred_accel) may cause a timeout and the server will close.