The main selling point of Linux is portability and by that code reuse across a wide array of use cases. Sure you could build a hardware abstraction layer for d

The main selling point of Linux is portability and by that code reuse across a wide array of use cases. Sure you could build a hardware abstraction layer for different processors and implement drivers on top of that, but you won't get the same traction/networking effect of Linux anytime soon. Same goes for software stacks (TCP/IP, USB, WiFi, file systems, etc) which have been running on billions of devices before if you use linux. The overhead of using Linux is in the range of 1-2MiB [1] so once your application requires external Ram because it doesn't fit the on-chip SRAM, you might as well use Linux. [1] http://www.emcraft.com/stm32f429discovery/what-is-minimal-footprint http://www.emcraft.com/stm32f429discovery/what-is-minimal-fo...