Secure boot reset (by wdog) issues

[vsiles]

Hi !

I recently "closed" one of our i.MX6q board (sec boot fuse & key burnt) to work on the secure boot, and so far, everything's fine. However, when I reset the board using wdog1, the board fails to boot quite often, being stuck in u-boot trying to load the init ramfs.

I don't have a log to produce at the moment, I'll do it asap (probably tomorrow), but maybe someone knows if we need to configure something (in the SNVS ?) before triggering a wdog reset on a closed board ?

Best wishes,

Vincent

[Yuri]

Hello,

  It is recommended to "remove power (Voltage source) to all components on the board in the event

of a processor reset. This avoids having to determine if a component critical to rebooting the processor

is in the necessary state to support a reboot. Components that fit this category include (but may not be

limited to):

• eMMC memory card (if the hardware RST_B pin is not connected.
• SD Card/socket (if the reset pin is not used to remove power to the SD Card)
• QSPI
• NOR
• LPDDR2/3 memory
  "

Does Your design meet this recommendation ?

Have a great day,

Yuri

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[vsiles]

Dear YuriMuhin_ng‌, I tried to check your information with the details here i.MX6 ARM Development Board  but I can't make sense of most of it, I'm not that familiar with hardware design.

Since our boards that are not closed for secure boot (along with this one, before it was closed) reboot correctly with wdog, I expect that we are in the correct configuration.

The reboot issue only happens with the closed board, so I think it is more "secure boot" related than hw design. Could you think of something about the difference between open and closed board which could prevent u-boot to correctly load the kernel from SD to DDR ?

Best,

V.

[Yuri]

Hello,

 Please double check boot log in the open state, especially hab events,

using Appendix A [Interpreting HAB Event Data from Report_Event() API]

of “HAB4_API.pdf” in the CST documentation.

Regards,

Yuri.

[vsiles]

Thank you very much for these information, I'll check that as soon as possible !