We are working with an UltraZED-EG unit.
The images are generated using PetaLinux 2019.1.
We load our BOOT.BIN to the QSPI and image.ub to the eMMC. When power is applied to the unit everything comes up get. However when we make a system configuration update and need to reboot the UltraZED-3EG hangs.
I have searched for others have similar issues, the results are usually dated a few years. The only reason I could find that it does fail is due to the MODE of the QSPI not be set back to "3" as Linux uses mode "4". This would explain why it fails to reboot.
I looked in the Linux Kernel, version 4.19, and it appears that the QSPI should be going back to MODE "3", but I am not seeing this happen with a reboot call. I thought about adding a reboot hook to the .shutdown protocol of the QSPI, but I haven't gone that far yet.
Since the hardware reset line for the QSPI is not available for this unit a software reset or setting the device in the right mode before rebooting is needed.
I have seen suggestions from patching the QSPI to using the #RESET line (which is not available for our part).
Any help to address the hangup issue would be greatly appreciated.