gPTP Sample Application¶
The gPTP sample application for Zephyr will enable gPTP support, registers gPTP phase discontinuity callback, enable traffic class support (TX multi queues) and setup VLANs (if enabled). The net-shell is also enabled so that user can monitor gPTP functionality.
The source code for this sample application can be found at:
Building and Running¶
A good way to run this sample is to run this gPTP application inside native_posix board as described in Networking with native_posix board or with embedded device like NXP FRDM-K64F or Atmel SAM-E70 Xplained. Note that gPTP is only supported for boards that have an Ethernet port and which has support for collecting timestamps for sent and received Ethernet frames.
Follow these steps to build the gPTP sample application:
# On Linux/macOS cd $ZEPHYR_BASE/samples/net/gptp mkdir build && cd build # On Windows cd %ZEPHYR_BASE%\samples\net\gptp mkdir build & cd build cmake -GNinja -DBOARD=<board to use> -DCONF_FILE=prj_base.conf .. ninja
The net-shell command “net gptp” will print out general gPTP information. For port 1, the command “net gptp 1” will print detailed information about port 1 statistics etc. Note that executing the shell command could affect the timing of the sent or received gPTP packets and the grandmaster might mark the device as non AS capable and disable it.
Setting up Linux Host¶
If you need VLAN support in your network, then the
samples/net/vlan/vlan-setup-linux.sh provides a script that can be
executed on the Linux host. It creates two VLANs on the Linux host and creates
routes to Zephyr. If you are using native_posix board, then
net-setup.sh will create VLAN setup automatically with this command:
./net-setup.sh -c zeth-vlan.conf
The OpenAVNU repository at https://github.com/AVnu contains gPTP daemon that can be run in Linux host and which can act as a grandmaster for the IEEE 801.1AS network. Note that OpenAVNU will not work with native_posix board as that board only supports software timestamping and OpenAVNU only supports hardware timestamping. See instructions at the end of this chapter how to run linuxptp daemon with native_posix board.
Get OpenAvnu/gPTP project sources
git clone firstname.lastname@example.org:AVnu/gptp.git
After downloading the source code, compile it like this in Linux:
mkdir build cd build cmake .. make cp ../gptp_cfg.ini .
gptp_cfg.ini file and set the neighborPropDelayThresh to 10000
as the default value 800 is too low if you run the gPTP in FRDM-K64F.
Then execute the daemon with correct network interface and the configuration file.
sudo ./gptp enp0s25 -F gptp_cfg.ini
Note that here the example network interface enp0s25 is the name of the network interface that is connected to your Zephyr device.
If everything is configured correctly, you should see following kind of messages from gptp:
INFO : GPTP [13:01:14:837] gPTP starting INFO : GPTP [13:01:14:838] priority1 = 248 INFO : GPTP [13:01:14:838] announceReceiptTimeout: 3 INFO : GPTP [13:01:14:838] syncReceiptTimeout: 3 INFO : GPTP [13:01:14:838] LINKSPEED_100MB - PHY delay TX: 1044 | RX: 2133 INFO : GPTP [13:01:14:838] LINKSPEED_1G - PHY delay TX: 184 | RX: 382 INFO : GPTP [13:01:14:838] neighborPropDelayThresh: 10000 INFO : GPTP [13:01:14:838] syncReceiptThreshold: 8 ERROR : GPTP [13:01:14:838] Using clock device: /dev/ptp0 STATUS : GPTP [13:01:14:838] Starting PDelay STATUS : GPTP [13:01:14:838] Link Speed: 1000000 kb/sec STATUS : GPTP [13:01:14:871] AsCapable: Enabled STATUS : GPTP [13:01:16:497] New Grandmaster "3C:97:0E:FF:FE:23:F2:32" (previous "00:00:00:00:00:00:00:00") STATUS : GPTP [13:01:16:497] Switching to Master
If Zephyr syncs properly with gptp daemon, then this is printed:
STATUS : GPTP [13:01:25:965] AsCapable: Enabled
By default gPTP in Zephyr will not print any gPTP debug messages to console.
One can enable debug prints by setting
CONFIG_NET_GPTP_LOG_LEVEL_DBG in the config file.
For native_posix board, use
linuxptp project as that supports
Get linuxptp project sources
git clone git://git.code.sf.net/p/linuxptp/code
ptp4l daemon and start it like this:
sudo ./ptp4l -2 -f gPTP-zephyr.cfg -i zeth -m -q -l 6 -S
default.cfg as a base, copy it to
gPTP-zephyr.cfg, and modify
it according to your needs.