Trouble when trying to run custom OS on AWS EC2 Metal instances

[rannnnnddiddddd]

Hi everyone,

I managed to get my hobby os running on AWS! I tested it across many different instance families and generations, e.g. t3.micro, c5.4xlarge, c8i.24xlarge, etc. And it works super well, I'm able to see output in serial console, whole networking stack is working (dhcp, tcp, etc.)

The trouble started when I tried to run it on metal instance, more specifically c5.metal - but issue is same on different instances too.

I cannot get VGA output as it's not supported on metal instances. I cannot get anything printing in serial console. I thought that the issue might be in some early boot code, but even if I start printing to serial right after GRUB2 calls the kernel I don't get anything.

I verified that the serial output works on metal instances with Ubuntu.

Any ideas on why this happens or how to fix it?

[Octocontrabass]

How are you detecting the I/O resources assigned to the serial port?