Using High Speed UART1 as Serial port on CoreBoot (MinnowBoard)

[Adrian Perez Resa]

Hello everybody,

I am newby with minnow board and CoreBoot.
I am trying to use HIGH Speed UART1 as Serial port on CoreBoot (SIO_UART 1 pins) with no success.

I have tried to configure CoreBoot with the following options:

-          Console > Index for UART port to use for console -> '0'

o   Baud rate 115200

But I don't know exactly what serial port I am using...

High speed UART 1 (SIO UART 1) is connected to JP1 Header in minnow Board.
However, Serial port seems to be always on the default debug UART (connector J4 on Minnow Board).
This Debug UART is attached at ATOM GPIOS GPIO_S0_SC_57 and GPIO_S0_SC_61 pins.

Does anybody know what options are necessary to change for using a different uart than the default one...?

Thanks in advance!

Best regards

[Ben Gardner]

Hi Adrian,

You are better off hooking up to the "Serial Console" port and using that.
http://wiki.minnowboard.org/MinnowBoard_MAX

If you really want to use one of the HS UARTs, then you have a bit of
work to do.
See src/drivers/uart/uart8250mem.c and note the use of
CONFIG_DRIVERS_UART_8250MEM_32.
You'd need to implement something similar to
src/soc/intel/skylake/romstage/uart.c, but for the E3800.
Not worth it, in my opinion, as the PCU UART works just fine.

Ben

On Tue, Apr 19, 2016 at 9:27 AM, Adrian Perez Resa  wrote:
> Hello everybody,
>
> I am newby with minnow board and CoreBoot.
>
> I am trying to use HIGH Speed UART1 as Serial port on CoreBoot (SIO_UART 1
> pins) with no success.
>
> I have tried to configure CoreBoot with the following options:
>      Console > Index for UART port to use for console -> ‘0’
>
> o   Baud rate 115200
>
> But I don’t know exactly what serial port I am using…
>
> High speed UART 1 (SIO UART 1) is connected to JP1 Header in minnow Board.
>
> However, Serial port seems to be always on the default debug UART (connector
> J4 on Minnow Board).
>
> This Debug UART is attached at ATOM GPIOS GPIO_S0_SC_57 and GPIO_S0_SC_61
> pins.
>
> Does anybody know what options are necessary to change for using a different
> uart than the default one…?
>
> Thanks in advance!
>
> Best regards