Guide for installing, setting up and building Zephyr hifi5s_ao_7 config

Note

The Zephyr RTOS port for Xtensa is available and supported by the Zephyr community. Therefore, any issues with running the RTOS on Xtensa should be addressed through the community support channel, on which multiple Tensilica users maintain an active presence. Cadence will assist in areas that appear to be caused by the Tensilica CPU or SDK but note that as Cadence does not directly maintain the Zephyr port, assistance from both the customer and the open-source community will likely be required.

Caution

This guide and the associated Zephyr patches for running Zephyr on Xtensa are provided for evaluation purposes only.

Installing and building Zephyr

This section contains a condensed guide for installing, setting up and building Zephyr using Xtensa SDK; find the full guide at: https://docs.zephyrproject.org/latest/develop/getting_started/index.html

• Make sure we are using bash; if not type bash at the command prompt.
• Export needed environment variables:

export SHELL=/bin/bash
export XTENSA_SYSTEM='/path/to/xtensa/XtDevTools/install/tools/RJ-2025.5-linux/XtensaTools/config'
export XTENSA_CORE='hifi5s_ao_7'
export ZEPHYR_TOOLCHAIN_VARIANT='xt-clang'
export TOOLCHAIN_VER=RJ-2025.5-linux
export XTENSA_TOOLCHAIN_PATH="${XTENSA_SYSTEM}/../../.."
export PATH="${XTENSA_SYSTEM}/../Tools/bin/:${XTENSA_SYSTEM}/../bin:${PATH}"

• Create workspace and active python3 environment:

cd ~
mkdir zephyrproject
python3 -m venv ~/zephyrproject/.venv
source ~/zephyrproject/.venv/bin/activate

• Install newer cmake (Optional if version >= 3.20.5):

pip install cmake

• Get Zephyr sources and install Python dependencies:

pip install west
west init ~/zephyrproject
cd ~/zephyrproject
west update
west zephyr-export
pip install -r ~/zephyrproject/zephyr/scripts/requirements.txt

• Checkout zephyr patch for HiFi5s config support:

cd zephyr/
git remote add foss-xtensa https://github.com/foss-xtensa/zephyr
git fetch foss-xtensa
git checkout v4.2.0-hifi5s_ao_7 -b hifi5s_ao_7
west update

Above steps complete installing and setting up Zephyr using Xtensa SDK (ie: toolchain). Note that installing the Software Development Kit (SDK) provided by the Zephyr project is optional: https://docs.zephyrproject.org/latest/develop/getting_started/installation_linux.html#building-on-linux-without-the-zephyr-sdk

Building Zephyr projects

This section lists steps to build Zephyr projects using Xtensa SDK.

• Activate python3 environment (Must be done only when we start working and the shell prompt is not yet prefixed with (.venv):

source ~/zephyrproject/.venv/bin/activate

• Export needed environment variables (Must be done only when we start working):

export SHELL=/bin/bash
export XTENSA_SYSTEM='/path/to/xtensa/XtDevTools/install/tools/RJ-2025.5-linux/XtensaTools/config'
export XTENSA_CORE='hifi5s_ao_7'
export ZEPHYR_TOOLCHAIN_VARIANT='xt-clang'
export TOOLCHAIN_VER=RJ-2025.5-linux
export XTENSA_TOOLCHAIN_PATH="${XTENSA_SYSTEM}/../../.."
export PATH="${XTENSA_SYSTEM}/../Tools/bin/:${XTENSA_SYSTEM}/../bin:${PATH}"

• Build sample project:

cd ~/zephyrproject/zephyr/
west build -b xt-sim samples/hello_world

• Execute sample project:

xt-run build/zephyr/zephyr.elf

• Clean project:

rm -rf build

This concludes the how-to-guide for installing, setting up and building Zephyr using Xtensa SDK.