Recommend way of full board reset (power-on-reset)

We are designing a new carrier board for a new product suitable with the colibri imx6ull and imx8 in the feature.
We want to be able to perform a full power-on reset remote without external input

What is the recommend way for a full board reset (power-on-reset like seen in u-boot) from within Linux.
Is it recommend to wire a gpio to the cpu reset pin (pin 26?) or should this be implemented on some other way?

Read up on both the power-up sequencing and reset recommendations in the carrier board design guide. Generally, the rails need to come up in the correct order, highest first +5V then +3.3V etc.

For reset, I wouldn’t personally hook directly to the reset pin on the SOM-CPU. That kind of “soft reset” would typically leave the USB devices, SDIO card still powered. This can cause problems with things like Wifi if not handled carefully. It’s probably safer to have an “always-on circuit” that power cycles the main power and lets the sequencing naturally take over.

Hi @j.janssen

@kswain has given already some good Inputs.

As described in Section 5.1.3 of the Datasheet of Colibri iMX6ULL, the Pin 26 is an Input to the module and is used for an external Reset of the module. You can use the Pin 87 for resetting the peripherals on your carrier Board, when the module is reset.

The recommended way of full board reset is either to trigger the watchdog or use the Soc watchdog output.

Best regards,