Source code of microcom

Hello everyone!

Do you know where I can find microcom source code?

I am using a teltonika gateway, with BusyBox v1.34.1
The microcom used by BusyBox is different from the ubuntu version.
Here's the output I have:

I'ld like to write my own serial program. As I am not used to that I wanted to start writing code based on microcom source code. But I can't find it anywhere.

Thank you for your help,

Francis

PS:

here:

https://git.busybox.net/busybox/tree/miscutils/microcom.c?h=1_34_1

Thank you very much!

It seems hard to extract the code, since it involves libbb.h, which involves again many libraries.
I can put my code inside it, but that's not proper...

Do you have a suggestion on how to use this code?

Note: I've been trying to write from scratch, but I am blocked, the read() remains permanently unavailable.