iMX8M Plus warm boot or warm reset

[gunnarsson]

Hi,

We want to do a "warm-reset" or "warm-boot" of an iMX8M Plus MPU.
By this we mean that we want to rest the MPU, and reload all firmware and OS, but retain parts of the external DDR memory-content.
We have experimented with this task, and found the following thread on the forum: https://community.nxp.com/t5/i-MX-Processors/i-MX8M-POR-when-reboot/m-p/1309342/highlight/true
It seems like the PMIC is reset on the nWDG signal, disabling power to the DDR and corrupting the memory. Our experiments supports this, we get data loss when resetting the only running CPU core from u-boot.

Warm-boot support for the iMX8M Plus platform seems to be lacking from u-boot, are there any plans to support this functionality?.

We realize that getting this to work would mean implementing support for warm-boot in u-boot.
The questions we have now, before we spend an inordinate amount of work on this is:

- Can a warm-boot be triggered and performed, without retraining the DDR, on the iMX8M Plus platform. We realize that is not supported, but can it be done?

Best regards,

Martin

[DavidFlir]

I came to the conclusion a warm reset can not be done.

I guess not getting an answer on this question in 2 years confirms it!