IMX8MP Custom Board: No UART Serial Console Output Logs

[subash_p]

Hi,

I’m working with a custom i.MX8MP board, where UART3 (ttymxc2) is configured as the serial console. To support this, I made the following changes in imx8mp-evk.dts

chosen {
    bootargs = "console=ttymxc2,115200 earlycon=ec_imx6q,0x30880000,115200";
    stdout-path = &uart3;
};

and also Modified imx8mp_evk.c and imx8mp_evk.h to switch from UART2 to UART3 and updated Boardconfig.mk to reflect the new console port.

This configuration works fine on Android 11.

However, after applying the same changes in Android 15 (imx-android-15.0.0_1.2.0), I no longer see any serial logs from UART3, not even U-Boot or early kernel messages.

Is there any additional configuration needed in Android 15 (U-Boot or kernel) to switch the serial console from UART2 to UART3?


Thanks & regards
Subash P

[Rita_Wang]

earlycon and stdout-path May Be Overridden

In Android 15, the bootloader or init scripts may override bootargs and stdout-path values defined in the Device Tree.

This can result in the kernel falling back to default UART (e.g., UART2/ttymxc1) even if DTS specifies UART3.