IMX8MP system crashing while writing to BMR register for Serial

[Saqib]

I am trying to write Serial driver for i.MX8 MP EVK Cortex M7 core. 
I can access most of the registers of the UART4 instance but when I try to write BMR value on BMR register to set the baud rate, the system gets traped into an exception.

I have checked that the Cortex M7 core domain has access to UART4. Moreover, no semaphore is required to access UART4. 

It would be very helpful if someone helps me figure out this problem.

[igorpadykov]

Hi Saqib

what dts file used in the case, one can try imx8mp-evk-rpmsg.dts where uart4 is disabled in linux:

https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8mp-evk-r...

Best regards
igor

[Saqib]

Hi Igor,

I am trying to enable UART4 as stdio for cortex M7 core. Moreover, I tried configuring UART1 and UART3 as well but encountering the same exception.

Regards,

Saqib

[igorpadykov]

Hi Saqib

one can look at uart4 examples in SDK_EVK-MIMX8MP available on

https://mcuxpresso.nxp.com/en/welcome

Best regards
igor