imx7 and hobbit board, second uart.

[mhanuel26]

@richard-hu @ray-chang
Hello,

I have a doubt about the step in the instruction, the M4 debug UART is defined as UART6, is that the second serial port you mention where the hello_world.bin example should print?

I am using iMX7 with hobbit carrier board, as my best understanding UART6 is the debug port, the same I use to see the console log and access u-boot. I have ran the demo but it did no show any console output from M4, it might be that A7 core is using UART6 resource too?

In this case I would like to know how can I use my own .dtsi file to disable UART6 for A7, but I cannot find the way this might be integrated in yocto.

Will appreciate your advice,

[mhanuel26]

@richard-hu @ray-chang
Hi,

For the pico hobbit board I found after running the demo that the second uart is located in the Mikrobus expansion header under UART3, thou I still don't understand how things get defined, for the pico imx7 I understand the UART6 debug output is defined in yocto as
SERIAL_CONSOLE = "115200 ttymxc4"
under pico-imx7.conf.

In freertos-tn the hello_world example for pico imx7 (imx7d_pioc_m4) defines a debug uart in board.h as
#define BOARD_DEBUG_UART_BASEADDR UART6

So how is the ttymxc# related to UART port on imx7? And how come UART3 is working for M4 demo?

I will appreciate your comments,