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It does seem like it at a first glance - these are Cortex-M microcontrollers which are really not suitable for running a full-fledged OS. They don't even have a

It does seem like it at a first glance - these are Cortex-M microcontrollers which are really not suitable for running a full-fledged OS. They don't even have an MMU, and they usually only have ~10-100KB of RAM on the chip. Plus, only some packages with >144 pins are able to memory-map external RAM chips like these evaluation boards do. It's a very cool and impressive project, but I wouldn't use it to write an application. Besides cost, the biggest reasons to use these instead of Cortex-A chips are power efficiency and simplicity, and implementing things like process isolation in software seems like throwing all that out the window. But on the other hand, if your device will be plugged in and power consumption isn't a huge concern, I could definitely see the appeal to having things like a Ruby interpreter or an X server running on your MCU. You could compile and deploy existing code, ideally. But I bet it would take more time to get all of that working well than it would to just write your application with an SDK and an RTOS. Also, I'm guessing this project predates the STM32MP1: https://www.st.com/en/microcontrollers-microprocessors/stm32mp1-series.html https://www.st.com/en/microcontrollers-microprocessors/stm32...

donquichotte 7y ago
The STM32F7 and H7 have data and instruction cache, IMO blurring the line between microcontrollers and SoCs.
vardump 7y ago
> They don't even have an MMU, But they might have an MPU. http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0439b/Chdecfea.html http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc....
- deleted 7y ago
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- leggomylibro 7y ago
  The MPU does look more capable than I'd originally thought, but it still seems very restrictive for general-purpose computing. 8-16 slots and difficult data boundary/width conditions: http://embedded-computing.com/articles/security-and-the-cortex-m-mpu/ http://embedded-computing.com/articles/security-and-the-cort... Like I said, this is a very impressive project and I admire the people who were able to make it happen, but in the context of writing an application it sort of seems like a solution looking for a problem. It reminds me of running Linux on the Nintendo DS. You can, and it's a fascinating toy, but the games are written bare-metal for a reason.
  - vardump 7y ago
    If the Linux kernel on STM32 has something important to offer for the application, like quicker time to market, while meeting the requirements and hitting price targets, why not? But yeah, if I needed to run Linux, I'd quickly pick something like Cortex A53, Cortex R52... etc. But hey, there might be a niche for Linux running on STM32. Doing embedded (and drivers) at dayjob.
StudentStuff 7y ago
The Cortex-M controllers just don't seem too competitive for networked applications or anything requiring complex code/IO. The cost for a full fledged ARM board is quite close to a STM32 with some addons, making me think one would be better off with something like an OrangePi Zero: https://www.aliexpress.com/item/32760774493.html https://www.aliexpress.com/item/32760774493.html

donquichotte 7y ago

The STM32F7 and H7 have data and instruction cache, IMO blurring the line between microcontrollers and SoCs.

vardump 7y ago

> They don't even have an MMU, But they might have an MPU. http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0439b/Chdecfea.html http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc....

deleted 7y ago
[deleted]
leggomylibro 7y ago
The MPU does look more capable than I'd originally thought, but it still seems very restrictive for general-purpose computing. 8-16 slots and difficult data boundary/width conditions: http://embedded-computing.com/articles/security-and-the-cortex-m-mpu/ http://embedded-computing.com/articles/security-and-the-cort... Like I said, this is a very impressive project and I admire the people who were able to make it happen, but in the context of writing an application it sort of seems like a solution looking for a problem. It reminds me of running Linux on the Nintendo DS. You can, and it's a fascinating toy, but the games are written bare-metal for a reason.
- vardump 7y ago
  If the Linux kernel on STM32 has something important to offer for the application, like quicker time to market, while meeting the requirements and hitting price targets, why not? But yeah, if I needed to run Linux, I'd quickly pick something like Cortex A53, Cortex R52... etc. But hey, there might be a niche for Linux running on STM32. Doing embedded (and drivers) at dayjob.

StudentStuff 7y ago

The Cortex-M controllers just don't seem too competitive for networked applications or anything requiring complex code/IO. The cost for a full fledged ARM board is quite close to a STM32 with some addons, making me think one would be better off with something like an OrangePi Zero: https://www.aliexpress.com/item/32760774493.html https://www.aliexpress.com/item/32760774493.html