hello brootux,
the logic is that if the retry_count reaches 0, then the CBoot will select another RootFS slot.
it only check and boot from next slot when retry count < 0; the default value of Rootfs_Retry_Count is 3.
there’s a background service, nv_update_verifier.service; in this service, it will trigger the l4t-rootfs-validation-config.service first, it provides an interface to users to customize when to say the boot is successful. If the validation script doesn’t exist or returns true, that means the rootfs boot up successful.
if the rootfs validation is true, then the nv_update_verifier.service will run /usr/sbin/nv_update_engine --verify, the nv_update_engine will increase the retry_count and update slot status.
here’s see-also topic for your reference, Topic 197124.
thanks