Bare Metal Code Development for iMX8M Mini

Hi, 

We are using iMX8M Mini (Part Number: MIMX8MM3CVTKZAA) which is built around Dual A53 Core (2xA53) and a M4 core. Our product will go to Avionics. Since aviation requires lot of certifications, we cannot use Linux (Yocto or similar) in our processor. We need to write Bare-Metal code for both the core from scratch.

I have couple of questions, 

1. I hope it is possible to develop Bare-metal code for A53 core. Will there be any restrictions?
2. Are there any free tools available from ARM for bare-metal code development? I heard about DS Studio, but it is a subscription based. 

I talked about this with NXP, but they didn't give any concrete answer. Hence, posting here.

Let me know if you need any more information. 

Thanks & Regards, 

Aravind D. Chakravarti, 

Lead Engineer, 

www.accord-global.com