Mbed OS Information needed

[NateD (Nathan DESCOMBES)]

Hello,

I want to get general information about Mbed OS (RTOS) that I didn’t succeed to find.

• Which SDK is used for Mbed OS ?

• What is the annual patches frequency and annual releases frequency ? (I currently see an average of 3 releases per year, do you confirm ?)

• Does Mbed OS got compliance to standards ?

• Does Mbed OS is certified (Avionic, Automotive…) ? Which certification ?

• Which cores (ARM Cortex A&M ) does Mbed OS support ?

Thanks,

Nathan

[RalphF (Ralph Fulchiero)]

Hi Nathan,

Thanks for your interest in Mbed. Here are some answers:

• Mbed doesn’t mandate a particular SDK, but it must be built with Arm Compiler 5, Arm Compiler 6, Gnu GCC Embedded or IAR as described here:

  • https://os.mbed.com/docs/mbed-os/v5.11/tools/index.html

• Note: A healthy number of SDKs are supported by an export operation from the Command Line Interface:

  • https://os.mbed.com/docs/mbed-os/v5.11/tools/exporting.html

• Releases are made quarterly and patches approximately every 2 weeks. Releases are available here:

  • https://os.mbed.com/releases/

• Mbed OS itself doesn’t comply to any safety standards or certifications. If you opt to use Compiler 5 or Compiler 6 then you do gain the benefit of using a tool that meets the following certifications:

  • https://developer.arm.com/products/software-development-tools/compilers/arm-compiler/safety

• Mbed is targeted at specific Arm boards more than actual Arm processors. The universe of processors covers almost every Cortex-M: Cortex-M0, M0+, M3, M4, M7, M23, M33. There are also a few boards based on the Cortex-A9. The full board list is available here:

  • Development boards | Mbed?

Let us know if you have any follow-up questions.

Regards,
Ralph, Team Mbed

[NateD (Nathan DESCOMBES)]

Thank you for your answers. I do have more questions.

• What is the minimal footprint of Mbed OS ?
• Does it use MMU and MPU ?
• How does the scheduler work (round-robin, preemption etc) ?
• Is there some data relating to reliability (context switch, interrupt latency etc) ? (Cortex M & A targeted)

Thanks,

Nathan

[NateD (Nathan DESCOMBES)]

If you could give me some information @RalphF it will be much appreciated.

Best regardes,

Nathan

[RalphF (Ralph Fulchiero)]

Hi Nathan,

Thanks for pinging me directly - somehow I missed your response perhaps when I was out-of-office. Here are responses to your questions:

1. The minimal footprint depends on the features that are needed. Mbed OS v5.12 will have a “bare metal” build option to facilitate reducing the footprint, and you will soon see some public collateral discussing this. A good article to read about customizing the build is here - where a build is brought down to 8KB of flash and less than 1KB of RAM:
   Reducing memory usage by tuning RTOS configuration | Mbed

2. Starting with v5.11 Mbed does utilize the MPU for most targets. You can read about the capability here:
   https://os.mbed.com/docs/mbed-os/v5.11/apis/mpu-management.html

3. Mbed is built on RTX v5 which utilizes a preemptive scheduler which is round-robin for threads with the same priority. You can read about RTX v5 on the Keil site:
   RTX v5 Implementation

4. Is there some data relating to reliability (context switch, interrupt latency etc) ?
   We’re sorry but we don’t have this information.

Regards,
Ralph, Team Mbed