General query - Does all rtos are microkernel ?

abhim1111 wrote on Monday, March 19, 2018:


I recently started using freertos and going through the documentation and refernce manual.
Previously, worked on linux kernel and have small exposure to Nucleus and Vxworks.

While going through the documentation I find similarities between freertos and Nuclues but find out that Vxworks was similar to linux kernel architecture wise and not very similar to freertos.

Upto my best knowledge freertos is a micro-kernel and does not have any user-space and kernel space concept but like linux, vxworks does have the same. Does this mean that vxworks is monolithic ?

Whether it is possible that a RTOS can be monolithic ?

Please help me in clearing my doubt.


rtel wrote on Monday, March 19, 2018:

I think the differentiation on microkernel Vs monolithic kernel is more
to do with the architecture of the kernel, rather than whether it
supports user space and kernel space or not. FreeRTOS does actually
have a memory protected version, where you have privileged and
unprivileged tasks.

abhim1111 wrote on Tuesday, March 20, 2018:

Thanks Richard for your reply.

Can you tell me FreeRTOS kernel follows which architecture either micro or monolithic ?

rtel wrote on Tuesday, March 20, 2018: