GenAVB/TSN

GenAVB/TSN is a generic AVB/TSN stack developed by NXP for NXP MCUs and MPUs. It is cross-platform, currently supporting Linux and FreeRTOS.

Supported hardware targets and configurations

This project supports several hardware targets and several different configuration modes. The table below summarizes the supported combinations, and their status for this specific release:

• O: supported by the project and validated for this release
• x: supported by the project, but not validated for this release
• empty cell: unsupported combination

Compilation target	Hardware target	AVB endpoint	TSN endpoint	AVB/TSN bridge
linux i.MX6	i.MX 6Q, i.MX 6QP, i.MX 6D, i.MX 6SX	x
linux i.MX6ULL	i.MX 6ULL	O
linux i.MX8	i.MX 8MP, i.MX 8DXL, i.MX 93	O	O
linux i.MX8	i.MX 8MM	O
linux LS1028	LS1028A			O
freertos RT1052	i.MX RT1052	x	x
freertos RT1176	i.MX RT1176	x	x
freertos RT1189 M33	i.MX RT1189			x
freertos i.MX8MM A53	i.MX 8MM	O	O
freertos i.MX8MN A53	i.MX 8MN	O	O
freertos i.MX8MP A53	i.MX 8MP	O	O

Features

• IEEE-802.1AS-2020 implementation, both time-aware Bridge and Endpoint support.
• IEEE-802.1Q-2018 (Clause 35) implementation, both Bridge and Endpoint Support
• IEEE-1722-2016 implementation, with MAAP support.
• IEEE-1722.1-2013 implementation, with support for Milan 1.1a mode.
• Binary protocol stacks running in standalone userspace processes.
• Public API provided by binary library plus header files.
• Example applications.

Repository structure

• api: the public API
• apps: source code and makefiles for example applications
• avdecc: IEEE 1722.1-2013/Milan 1.1a component stack
• avtp: IEEE 1722-2016 component stack
• common: common code
• configs: configuration files
• doc: documentation
• gptp: IEEE 802.1AS-2020 component stack
• freertos: FreeRTOS specific code
• linux: Linux specific code
• maap: MAAP component code
• public: common code shared between applications and stack
• srp: IEEE 802.1Qat-2010 component stack

Build

GenAVB/TSN is using Cmake to generate build system.

Some preliminary configuration is required to provide path to the toolchain, staging directory and external components.

Local configuration files can be included by the build system in order to to define some variables specific to the developer environment. The local config file name is ./local_config_${target}.cmake

Build requirements

• Linux host system and development tools (git, make, doxygen for the docs, ...)
• An ARM gcc toolchain is sufficient for the stack. However building the linux applications requires a more complete cross-compilation SDK (because of additional dependencies such as alsa, gstreamer and qt5/qt6).
• AVB endpoint builds depend on custom changes to the Linux kernel and specific Yocto distribution: https://www.nxp.com/design/software/development-software/real-time-edge-software:REALTIME-EDGE-SOFTWARE
• FreeRTOS builds require additional MCUXpresso SDK software: https://www.nxp.com/design/software/development-software/mcuxpresso-software-and-tools-/wired-communications-middleware-for-nxp-microcontrollers:WIRED-COMM-MIDDLEWARE?fpsp=1&#avb-tsn

FreeRTOS

Currently GenAVB/TSN stack support only ARM gcc toolchain for FreeRTOS targets. To be able to build the stack, ARMGCC_DIR environement variable pointing to arm-gcc toolchain must be defined.

export ARMGCC_DIR=/path/to/gcc-arm-none-eabi-xxx

The local config file should define:

set(FREERTOS_SDK "/path/to/freertos_MCUXpresso_SDK" CACHE PATH "Path to MCUXpresso SDK")
set(FREERTOS_APPS "/path/to/freertos_application" CACHE PATH "Path to FreeRTOS application repository")

Linux

The Linux target is usually built using a complete toolchain, which helps setting most of the environment variables required for cross-compilation. In the case of a Yocto SDK/toolchain for example, the following command will setup $CROSS_COMPILE as well as other related environment variables:

source /path/to/yocto/toolchain/environement-setup-xxx

The local config should however define:

set(KERNELDIR "/path/to/linux_avb" CACHE PATH "Path to Linux kernel")

Build commands

Syntax is:

cmake . -B<build directory> -DTARGET=<target name> -DCONFIG=<config name>
make -C <build directory> install

The GenAVB/TSN stack also provides a couple shell functions with auto-completion to facilitate the build process. Usage is

# Setup environment, see Build paragraph above
source environment-genavb
make_genavb [target] [config_list]
clean_genavb [target]

where target and config_list are optional. If no config_list is defined, all available configurations for specified target are built. If no target is specified the default is linux_imx6. config_list is of the form: configA configB ..., with one or more members.

To generate doxygen HTML documentation:

cmake . -B<build directory> -DTARGET=<target name> -DCONFIG=<config name>
make -C <build directory> doc_doxygen

The generated documentation is available under <build_directory>/doc To install documentation under a custom path: use cmake variable -DDOC_OUTPUT_DIR=<custom absolute path>

Generated binaries

The generated binaries are installed under <build directory>/

Installing binaries to target

Linux

Copy the content of <build directory>/target/ to the root directory of the target filesystem

FreeRTOS

Refer to the FreeRTOS application README.