bradyte

Installing the Software

After feeling like I was riding down rainbow road, figuring our how to install the software brought me back down to Earth. Now granted, the Linux TSN Documentation was a really great guide once I understood how to adopt it to my CM4 system.

System Requirements

This tutorial has been validated on two desktop machines with Intel(R) Ethernet Controller I210 connected back-to-back and Raspberry Pi kernel version Linux raspberrypi 6.12.47+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1 (2025-09-16) aarch64 GNU/Linux.

My Install Journey

I will be walking through the Linux TSN Documentation and updating the commands for sections I needed to update. Otherwise, the existing commands are correct.

As with any Pi project, update to with the latest security patches and software updates.

sudo apt update && sudo apt upgrade

Starting from the Plugin Installation, I installed the necessary packages:

sudo apt install build-essential git meson flex bison \
        libcmocka-dev autoconf libtool autopoint libncurses-dev \
        libpulse-dev

Info: I received an error regarding the glib2.0 that the system was unable to locate the package. The notes from Debian encourage moving to the libglib2.0-dev package which is installed as a dependency package anyway.

Next, it's required have the libavtp package installed when compiling ALSA and Gstreamer. I found a good explanation from ÆSR Lab - Sound Project Labratory about the correct order of operations.

I proceeded to install the libavtp package.

git clone https://github.com/Avnu/libavtp.git
cd libavtp/
meson setup build
sudo ninja -C build install

Info: When running just meson build, I received an error saying that running the setup command without the word setup is deprecated so I updated the command.

ALSA Plugin

To install ALSA library (alsa-lib) on Debian/Ubuntu systems, use sudo apt-get install libasound2 for the runtime library or sudo apt-get install libasound2-dev for development files.

TODO: confirm alsa-lib vs libasound2

The ALSA project includes gitcompile script which is recommended to use by the INSTALL documentation so the commands were updated.

Step 1: Start with the core libraries from alsa-lib project:

git clone https://github.com/alsa-project/alsa-lib.git
cd alsa-lib/
./gitcompile --prefix=/usr/local
sudo make install

Step 2: Install the utility tools from alsa-utils project:

git clone https://github.com/alsa-project/alsa-utils.git
cd alsa-utils/
./gitcompile --prefix=/usr/local --disable-nls
sudo make install

Info: For alsa-utils install, I added --disable-nls to ./gitcompile which removed some NLS errors

Step 3: Install the plugins from alsa-plugins project

git clone https://github.com/alsa-project/alsa-plugins.git
cd alsa-plugins/
./gitcompile 
./configure --prefix=/usr/local --enable-aaf
sudo make install

Info: For alsa-plugins install, I added --enable-aaf to ./gitcompile to be able to install the plugins alongside system packages

TODO: figure out why I need to

#sudo cp -a /usr/local/lib/alsa-lib/. /lib/aarch64-linux-gnu/alsa-lib/
# I may only need to do this one
sudo cp -a /usr/local/lib/. /lib/aarch64-linux-gnu/

You can confirm everything is correct so far looking at the console output and seeing:

AAF plugin:         yes

Step 4: Regenerate the shared library cache after manually installing libraries

sudo ldconfig

VLAN Configuration

All the commands worked for me but on the Pi, the I210 NIC was the eth1 interface so I changed all the commands to match. This caused a lot of debugging issues missing this detail.

sudo ip link add link eth1 name eth1.5 type vlan id 5 \
        egress-qos-map 2:2 3:3

sudo ip link set eth1.5 up

Qdiscs Configuration

Note: these qdiscs enable a transmission algorithm and should be configured on transmitting end-stations (Talker systems). They are not required on the receiving end-stations (Listener systems).

MQPRIO Configuration

sudo tc qdisc add dev eth1 parent root handle 6666 mqprio \
        num_tc 3 \
        map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
        queues 1@0 1@1 2@2 \
        hw 0

CBS Configuration

sudo tc qdisc replace dev eth1 parent 6666:1 handle 7777 cbs \
        idleslope 98688 sendslope -901312 hicredit 153 locredit -1389 \
        offload 1

sudo tc qdisc replace dev eth1 parent 6666:2 handle 8888 cbs \
        idleslope 3648 sendslope -996352 hicredit 12 locredit -113 \
        offload 1

ETF Configuration

error does not like this for some reason

sudo tc qdisc add dev eth1 parent 7777:1 etf \
        clockid CLOCK_TAI \
        delta 500000 \
        offload

sudo tc qdisc add dev eth1 parent 8888:1 etf \
        clockid CLOCK_TAI \
        delta 500000 \
        offload

Cyclic test

https://wiki.linuxfoundation.org/realtime/documentation/howto/tools/rt-tests#compile-and-install

sudo apt install rt-tests

TAPRIO Configuration

sudo tc qdisc replace dev eth1 parent root handle 100 taprio \
        num_tc 3 \
        map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
        queues 1@0 1@1 2@2 \
        base-time 1000000000 \
        sched-entry S 01 300000 \
        sched-entry S 03 300000 \
        sched-entry S 04 400000 \
        flags 0x1 \
        txtime-delay 500000 \
        clockid CLOCK_TAI

ETF Offload

sudo tc qdisc replace dev eth1 parent 100:1 etf \
        clockid CLOCK_TAI \
        delta 500000 \
        offload \
        skip_sock_check

note may need to restart ptp4l or wait until everything is configured

Time Synchronization

# run on both
sudo ptp4l -i eth1 -f ~/src/linuxptp/configs/gPTP.cfg --step_threshold=1 -m

sudo timedatectl set-ntp false

sudo pmc -u -b 0 -t 1 "SET GRANDMASTER_SETTINGS_NP clockClass 248 \
        clockAccuracy 0xfe offsetScaledLogVariance 0xffff \
        currentUtcOffset 37 leap61 0 leap59 0 currentUtcOffsetValid 1 \
        ptpTimescale 1 timeTraceable 1 frequencyTraceable 0 \
        timeSource 0xa0"

sudo phc2sys -s eth1 -c CLOCK_REALTIME --step_threshold=1 \
        --transportSpecific=1 -w -m

sudo ptp4l -i eth1 -f ~/src/linuxptp/configs/automotive-master.cfg --step_threshold=1 -m
sudo ptp4l -i eth1 -f ~/src/linuxptp/configs/automotive-slave.cfg --step_threshold=1 -m

Confirm NTP is not running!!! An NTP service may be running and changing the system clock. On systems with systemd, run:

GStreamer examples

sudo gst-launch-1.0 clockselect. \( clock-id=realtime \
    audiotestsrc samplesperbuffer=12 is-live=true ! \
    audio/x-raw,format=S16BE,channels=2,rate=48000 ! \
    avtpaafpay mtt=50000000 tu=1000000 streamid=0xAABBCCDDEEFF000B processing-deadline=0 ! \
    avtpsink ifname=eth1.5 address=01:AA:AA:AA:AA:AA priority=2 processing-deadline=0 \)

sudo gst-launch-1.0 clockselect. \( clock-id=realtime \
    avtpsrc ifname=eth1.5 address=01:AA:AA:AA:AA:AA ! \
    queue max-size-buffers=0 max-size-time=0 ! \
    avtpaafdepay streamid=0xAABBCCDDEEFF000B ! audioconvert ! autoaudiosink \)


export GST_DEBUG=3
# Or a higher level for more detail:
export GST_DEBUG=4
# Then run your GStreamer command or application
gst-launch-1.0 [your pipeline description]

for utils add 
apt-get install gstreamer1.0-plugins-base-apps

The GStreamer Way From a WAV File To stream contents from a WAV file, use the filesrc element and run the command:

sudo gst-launch-1.0 clockselect. ( clock-id=realtime
filesrc location=~/Flamagra-01-004-More.wav ! wavparse ! audioconvert !
audiobuffersplit output-buffer-duration=12/48000 !
avtpaafpay mtt=50000000 tu=1000000 streamid=0xAABBCCDDEEFF000B processing-deadline=0 !
avtpsink ifname=eth1.5 address=01:AA:AA:AA:AA:AA priority=2 processing-deadline=0 )

removing qdiscs

sudo tc qdisc del dev eth1 root
sudo tc -d qdisc show dev eth1