[i.MX8M Plus] merge A53 and M7 debug console in one uart port

[sophiehu]

Hi NXP,

We are using i.MX8M plus in our design. Since A53 uses uart2 as debug port and M7 uses uart4 as debug port, we need to place two console port for user to debug both of them which means we need larger pcb. Is it possible to merge these two debug console ports in one uart port?

I also find tis reference:
https://community.nxp.com/t5/i-MX-Processors/IMX8M-Mini-A53-core-UART-debug/m-p/1162639
from imx8mp-evk.dts I know the dts define uart2 as A53 console port.
But I still don't know how to merge them.

Is it possible to merge M7 console port in the uart2 also and how to implement that?

Best Regards,
Sophie

[sophiehu]

I want to change both A53 and M4 debug port in uart1 and config uart2/uart3/uart4 as normal uart ports for A53.
Is it possible?

[joanxie]

if you want  A core and M core to access one uart, this isn't a reasonable, you need assign the uart to A core or M core every time

[sophiehu]

I see.
I will give up debug console of M4.
Can I assign all uart ports (uart1 to uaty4) to A53?
There're uart1/uart2/uart3 configuration in dts.
Do I just create uart4 configuration in dts?
What else do I need to do to assign uart4 to A53?

[joanxie · Accepted solution]

refer to this:

https://community.nxp.com/t5/Blogs/How-to-Change-i-MX8MM-evk-Linux-Debug-UART/ba-p/1243938

[joanxie]

firstly, uart4 is for M4 core, not M7, do you mean that you want to change uart4 debug port for A53 instead of M4, right?