Zephyr RTOS on STM32 MCUs: Open-Source Software

STMicroelectronics' role in the Zephyr ecosystem

Zephyr is an open-source RTOS ecosystem. As a silver member, STMicroelectronics collaborates with the Zephyr community and plays a key role in the ecosystem by contributing its STM32 expertise and serving as a maintainer for the STM32 code base.

ST’s contribution is based on three axes:

Maintaining the STM32 code base: introducing new STM32 series, ensuring consistency across STM32 devices, and updating STM32 code to follow both Zephyr and STM32Cube evolutions
Ensuring code stability by running daily test campaigns (10K tests every night on a selection of STM32 targets) on a 24/7 automated test bench
Supporting the community on the STM32 code base: reviewing contributions, fixing issues, and answering questions

Zephyr APIs are ported on top of STM32Cube HAL or LL, depending on the STM32 peripherals.

More than 190 boards with STM32 are supported. You can get a precise coverage selecting your STM32 device in SoC filter.

Find your board

For each board, you will find a table listing all supported features with the corresponding Zephyr drivers.

Getting started with Zephyr on STM32

Developing on Zephyr will require you to learn new concepts, such as Kconfig and Device Tree for the system configuration, or CMake and West for the build system.

To get started, you can refer to the Zephyr online documentation .

Technical support

ST contributes and provides support on Zephyr low-level APIs, corresponding to items in navy blue in the below diagram.

Here is the list of STM32 peripherals and resources supported by Zephyr:

ADC, AES, backup SRAM, battery backed RAM (BBRAM), DMA, CAN, CRYP, DAC, DCMI, digital temperature sensor, EEPROM, Ethernet, EXTI, FMC, GPIO, HSEM, I2C, I2S, I3C, interprocessor communication (IPCC), LCD-TFT display (LTDC), MDIO, MIPI display serial interface (DSI), OctoSPI/QuadSPI/HSPI, quadrature decoder sensor (QDEC), reset and clock controller (RCC), random number generator (RNG), real-time clock (RTC), SDMMC, SPI, low-power timers (LPTIM), timers, touch sensing controller (TSC), LPUART, UART, USART, USB Power Delivery, USB, watchdog.

STM32 wireless products are supported with:

Bluetooth® LE HCI driver on STM32WB0, STM32WB and STM32WBA series,
LoRa PHY driver on the STM32WL series.

Due to its open-source nature, the Zephyr ecosystem and APIs evolve daily. There may be delays between the availability of a new API and its support across all STM32 devices.

For questions, you can join the active STM32 Zephyr community on the #STM32 channel of the Zephyr discord group or visit the Zephyr GitHub to report issues or submit pull requests.

Several ST Authorized Partners are experts in Zephyr and STM32, offering application development services or training on Zephyr. See ST Authorized Partners listed below.

See ST Authorized Partners listed below.