SW4STM32 and SW4Linux fully supports the STM32MP1 asymmetric multicore Cortex/A7+M4 MPUs

   With System Workbench for Linux, Embedded Linux on the STM32MP1 family of MPUs from ST was never as simple to build and maintain, even for newcomers in the Linux world. And, if you install System Workbench for Linux in System Workbench for STM32 you can seamlessly develop and debug asymmetric applications running partly on Linux, partly on the Cortex-M4.
You can get more information from the ac6-tools website and download (registration required) various documents highlighting:

System Workbench for STM32

need a simple MQTT client for stm32f446 with no OS

thanks for your response! however there is something that i do not understand.For example for IwIP, it has functions such as mqtt_subscribe. Nucleo f446re does not have an inbuilt GSM module right? so im using an external sim800l. how does mqtt_subscribe know which interface to use to send packets? it doesen’t know the AT commands also. so how come people on the ST forums say that it is not dependent on the hardware and that i can use any mqtt client?