How i can change U-Boot console to UART2 on Apalis iMX6?

Hi

You need to change the pinmuxing to the pins you want to use for UART2. And you have to configure the driver to use UART2.
Have a look at this patch.

You likely will want UART2 in the Linux kernel as well. That one is chosen from the kernel cmdline.
This patch changes the U-Boot environment accordingly.

Systemd will automatically spawn a login console for UART2 because of the cmdline.

But it will also spawn an additional login console on UART1 because of the file ‘/etc/systemd/system/getty.target.wants/serial-getty@ttymxc0.service’. Delete that file from the rootfs or build your own rootfs with the SERIAL_CONSOLE assignment changed in the machine configuration file.

Max

PS.:
If one uses U-boot 2016.11-toradex one needs to change in addition to the above the platform data.