Which Operating Systems are mostly used on STM32MPUx products? Your experience? Any bare-metal?

[LCE]

Heyho,

until now I have only used the STM32 MCUs, from L01x, to G4,  up to H7 (single core), always bare-metal.

We're now thinking about scaling up to some MPU, for more processing power, and also for some faster interfaces (mainly gigabit ethernet).

From my first investigations about the MPUs, I'm not sure if we can "afford" this on the personnel side, due to the complexity and very probably the necessity to use an OS (real-time is a must, at least "real" enough for multi-channel low latency audio).

We have an overworked software department, and no "embedded SW" people, and I'm more of a hardware designer who can do some basic C stuff.

So I'd like to know:

• which OSs are mostly used on the MPUs, or which are you using
• how's your experience with these
• what's the learning curve for newbees
• anybody working bare-metal with the MPUs, and how's that

Thanks in advance!

[loveforcircuits]

MPUs usually run Embedded Linux. Linux dominates Cortex-A class systems. RTOS options include QNX and VxWorks. FreeRTOS is mostly MCU-focused. Bare-metal on MPUs is possible but complex.
You must handle MMU and cache coherency. Boot chains and device trees add complexity.
Linux offers strong Gigabit Ethernet support. PREEMPT_RT enables low-latency audio performance.
Learning curve is steep for MCU developers. Expect several months to become productive. Buildroot is simpler than Yocto initially. Without Linux expertise, project risk increases significantly. Hiring embedded Linux help reduces schedule risk.

[Erwan SZYMANSKI]

Hello @LCE ,
@loveforcircuits already made a quite good summary, and I am fully aligned.

Indeed Linux represents 95% of what is running on STM32MPU (Cortex Ax) side, as there is a massive support and examples for this. Integration of Linux is also very easy due to what is currently provided by STMicroelectronics with its default distribution, OpenSTLinux. Do not hesitate to come on wiki to get more information https://wiki.st.com/stm32mpu/wiki/Main_Page.

Bare metal on Cortex A is also possible on MP13, we already provide some stuff here for that:

• STM32MP13: https://wiki.st.com/stm32mpu/wiki/STM32CubeMP13_Package

Zephyr is also a possible solution based on MP13 Bare Metal package, this is supported by the community: https://docs.zephyrproject.org/latest/boards/st/stm32mp135f_dk/doc/index.html

From existing experiences, we already have some example of customers going from MCU to MP13-BM for Mips / performances reason. This is the more classical transition we see.

Kind regards,
Erwan.