topic Re: iMX6UL reset reason in i.MX Processors

iMX6UL reset reason

aermakov — Fri, 30 Aug 2019 08:22:41 GMT

I try to detect last reset reason in u-boot.

I use iMX6UL-evk evaluation board, default configs for u-boot and buildroot for this board.

To test last reason reset feature I folow these steps:

1) Booting in buildroot.

2) Disabling watchdog daemon.

3) Board resets on watchdog timeout.

In U-boot debug I can see reset reason "Reset cause: POR", and it does not change even if the reset occurred due to a watchdog timeout. To detect reset cause u-boot reads "SRC Reset Status Register (SRC_SRSR)".

I have written u-boot module which reads " Watchdog Reset Status Register (WDOGx_WRSR)", and it tells same (POR reason)

Do I need to do something to detect reset reason?

Re: iMX6UL reset reason

igorpadykov — Fri, 30 Aug 2019 10:18:12 GMT

Hi Alexey

WDOGx_WRSR is only option to know reset reason, however on i.MX6UL EVK

wdog is connected to U708 (UM805RE) SPF-28617.pdf i.MX6UL EVK schematic,

operating in the same manner as POR and resetting whole board.

Best regards
igor
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Re: iMX6UL reset reason

aermakov — Fri, 30 Aug 2019 10:35:08 GMT

Thank you for answer. And what should I implement in my custom board to use this option?

Re: iMX6UL reset reason

igorpadykov — Fri, 30 Aug 2019 11:35:18 GMT

not to reset whole board.