[iMX8QM-MEK] How to stop: Power Mode Switch Application

[sushi_happy]

Hi,all.

When connecting to the RS-232C connector (J37) of imx8qm-mek, a message about the "Power Mode Switch" application is output.
I want to stop this application.
What should I do?

#################### Power Mode Switch Task ####################

Build Time: Aug 10 2021--13:43:40
Core Clock: 264000000Hz
Power mode: RUN

Select the desired operation

Press A for enter: RUN - Normal RUN mode
Press B for enter: WAIT - Wait mode
Press C for enter: STOP - Stop mode
Press D for enter: VLPR - Very Low Power Run mode
Press E for enter: VLPW - Very Low Power Wait mode
Press F for enter: VLPS - Very Low Power Stop mode
Press G for enter: LLS - Low Leakage Stop mode
Press H for enter: VLLS - Very Low Leakage Stop mode
Press R for using WDOG trigger M4 partition reset.

Waiting for power mode select..

[ChrisC05]

Hello,

Is there any update to this? I am running into the same issue.

[sushi_happy]

@ChrisC05 

I'm not currently evaluate this, so I haven't tested it, but please try the following method.

Enter commands on the serial console

- Stop the application

systemctl stop power-mode-switch

- Stop the application from starting automatically

systemctl disable power-mode-switch

Similarly, you can write

exec systemctl stop power-mode-switch

in the on boot section of init.rc.

Please let me know if there are any developments.

[ChrisC05]

Hey @sushi_happy

Thank you for responding.

I tried your instructions however the power mode switch application seems to be loaded on the M4 core before U-boot even gives me the chance to enter auto-boot, and using `systemctl disable power-mode-service` returns "Failed to disable unit: Unit file power-mode-switch.service does not exist." in the kernel.

I'm not quite sure how to proceed from here.

[sushi_happy]

@ChrisC05 

Sorry.

By default, resources are assigned to User CM4_1 for Power_Mode_Switch and the settings cannot be changed.

m4_1_image.bin  (\android_build\vender\nxp-opensource\imx-mkimage\iMX8QM)

I Think this file contains information about Power_Mode_Switch.

Download the MCUXpresso SDK, build an empty source code like

main()
{
    while(1){
    }
}

and replace it with the generated .bin file.

Power_Mode_Switch should stop.

If you write something like

printf("Hello World\n");

A string will be output.

However, this is information from an older version, so there may be differences.

Also, if you want to use ttyLP2, etc., it is assigned to a different M4 core, so communication will not be possible with just the above changes.

[Rita_Wang]

Sorry for miss your thread and late reply.

The ttyLP2 is enabled by default BSP. You can test it.

The hardware for ttyLP2 is on the base board as J37(DB9 connector).

The hardware for ttyLP2 is on the base board as J37(DB9 connector). 

you need a usb to  uart DB9 to connect the J37(DB9 connector).

[Rita_Wang]

The ttyLP2 is enabled by default BSP. You can test it.

The hardware for ttyLP2 is on the base board as J37(DB9 connector).

The hardware for ttyLP2 is on the base board as J37(DB9 connector). 

you need a usb to  uart DB9 to connect the J37(DB9 connector).

[sushi_happy]

Thank you @Rita_Wang .

But,I know that.

Please tell me how to disable it.