Mm-iot-sdk Code Size?

Software
1

Hello! Last topic for now I think - a lot of questions as we get into development with Morse Micro parts.

We are in process of MCU part selection for hosting an MM8108 modem as part of the main device application. We’ve seen in documentation and a forum topic that the minimum recommended host flash memory size is 2MB (256KB RAM) in order to use the modems in the currently supported softMAC mode, with mm-iot-sdk.

As I’ve built the examples I am able to build from the CMSIS pack for the MM dev kit, I’m seeing binary sizes hovering around 1MB. This leads to a question… is the 2MB recommendation given with a large margin to support user application code? The wording in mm-iot-sdk release documentation sounds like 2MB is an absolute minimum, and that using more than the basic functions of the driver (such as TLS) may require even more memory. But that doesn’t add up with what I’ve seen in the example app build outputs for the reference STM32U5. Do any examples (such as the aws_iot example configuration which I’m currently unable to build, see here) demonstrate usage of other components that will blow up the application size?

Best,

Tony

2

Hi @tjose

Effectively yes. From the table in the mm-iot-sdk release notes, section 3.1, the numbers are marked as “recommended”.

We used to give out minimum numbers for what the library itself would consume, only to have users under resource their hosts for their applications :smiling_face_with_tear:.

I believe the 2MB number comes from some of our example apps consuming >1MB, and 2MB is the most common flash size up.

If I recall correctly, the aws_iot samples require the most resources. It will fit well within a 2MB flash limit though. I’ll look at the failures in your other thread shortly.