i.MX ProcessorsのトピックIMX93 - Secure RTC from BBSM support in Linux ?

IMX93 - Secure RTC from BBSM support in Linux ?

taragon — Fri, 18 Apr 2025 12:52:42 GMT

Hello,

In the imx93 datasheet I can see that there is a internal RTC within the BBSM part. It seems that this rtc is controlled by the ele:

Battery Backed Security Module (BBSM)
• Secure real-time clock (RTC)

Is there any way to use it with Linux thru the ELE API or other? ideally, is there a kernel driver on track?

Manuel_Salas — Fri, 18 Apr 2025 13:58:56 GMT

I hope you are doing very well.

It seems that Linux can not control the RTC BBSM directly, and also, the ELE API just have the Enable RTC command:

So, it is recommended to use an external RTC as you can see on EVK or i.MX93 FRDM board:

It is using the PCF2131, and there is a driver in our BSP.

Unfortunately there is not a Linux driver for the RTC on BBSM of i.MX93.

Best regards,

Salas.

taragon — Fri, 18 Apr 2025 14:23:37 GMT

Thanks for your answer. Is it something likely to be implemented in a near future? It is BOM-cost friendly...