chaning the Debug port i.MX8QXP

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chaning the Debug port i.MX8QXP

3,357 Views
oferausterlitz
Senior Contributor II

Hi,

We are using the L4.14.78_1.0.0_ga release and are trying to change the Debug port of the i.MX8QXP from UART0 used in the MEK reference board to UART3, without success.

The pins we are trying to use are:

SC_P_SCU_GPIO0_00_ADMA_UART3_RX
SC_P_SCU_GPIO0_01_ADMA_UART3_TX

 

Is there a known issue regarding this, or are we missing something?

Can you please guide us how to do this change?

 

Thanks!

6 Replies

1,868 Views
eric_lee1
Contributor II

Hi

Did you get this questions solved?

I am also want to use the following pin as my u-boot debug port and make changes in u-boot accordingly.

SC_P_SCU_GPIO0_00_ADMA_UART3_RX
SC_P_SCU_GPIO0_01_ADMA_UART3_TX

There is nothing outputs. While using UART0 and UART1 are no problem. Do I need to make change to scfw? 

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karina_valencia
NXP Apps Support
NXP Apps Support

igorpadykov‌, please continue with the follow up.

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igorpadykov
NXP Employee
NXP Employee

I escalated your questions on

chaning the Debug port i.MX8QXP 

Best regards
igor

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2,388 Views
igorpadykov
NXP Employee
NXP Employee

Hi Ofer

I received answer below:

------------------

There should be no changes to the SCU FW itself. U-Boot (and Linux) make calls to the SCFW API to configure hardware managed by the SCU (i.e., LPUARTs) instead of reading/writing registers directly.


For obvious reasons we'll deal with U-Boot first.


In the board file (for the MEK it's board/freescale/imx8qxp_mek/imx8qxp_mek.c), first make sure UART3 pads are configured in setup_iomux_uart() and clocks are configured an enabled in board_early_init_f(). Searching for (regex) uart.*0 in the board file turns up references in board_quiesce_devices(). Configure CONFIG_SERIAL_LPUART_BASE in your board config file (include/configs/imx8qxp_mek.h for the MEK). There are several environment variables involving the console including boot args passed to the kernel.


Then you'll need to make similar changes in the U-Boot device tree: arch/arm/dts/fsl-imx8qxp*.dts*. MUX and clocks should be configured, though you might need to enable (status = "okay";) lpuart3. Don't forget to include CONFIG_FSL_LPUART=y in your defconfig file.


It might help for you to share with me what you have attempted so far, though it will be difficult for me to help directly unless I can figure out a way to bring out UART3 (or another LPUART) on my MEK. What are the failure symptoms? Just "silence" on the serial line or do you observe U-Boot resets? Do you have a hardware debugger? That makes board bring-up significantly easier.

------------------

so first one can try to change uart0 to uart3 in uboot:

uboot/board/freescale/imx8qxp_mek/imx8qxp_mek.c

imx8qxp_mek.c\imx8qxp_mek\freescale\board - uboot-imx - i.MX U-Boot 

use sect.3.3.1 Using JTAG tool for debugging attached Porting Guide.

uart3 example for i.MX8QXP toradex colibri board

colibri-imx8qxp.c\colibri-imx8qxp\toradex\board - u-boot-toradex.git - U-Boot bootloader for Apalis ... 

build steps

Build Apalis iMX8/Colibri iMX8X Boot Image/Linux from Scratch 

Best regards
igor

2,387 Views
igorpadykov
NXP Employee
NXP Employee

Hi Ofer

pin SC_P_SCU_GPIO0_00_ADMA_UART3_RX use UART3 from ADMA

complex, not SCU. SCU has only one UART according to Figure 13-1. Simplified Block Diagram

i.MX8DQXP Reference Manual
https://www.nxp.com/docs/en/reference-manual/IMX8DQXPRM.pdf

In general may be useful to check scfw documentation included in

SCFW Porting Kit

or System Controller Unit (SCU) Introduction for i.MX 8QXP MEK - i.MXDev Blog 

Best regards
igor
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oferausterlitz
Senior Contributor II

Hi

Sorry for not being clear enough.

We are trying to use UART3 as the console of U-Boot (and Linux) - not in the SCU FW.

Can you please confirm that there is no known issue doing so?

Can you please guide us how to do this?

Is there anything we should change in the SCU FW or only in U-Boot itself?

(We can provide our non-working U-Boot code changes if needed)

Thanks.

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