Info provided in Training slides:

Refers to a disaster recovery image that is launched if the firmware image is invalid due to corruption of other reasons. When the device is running an DRI image, then it is DRI mode. If a normal firmware image is running, then it is in normal mode. 

On the other hand, RDK Components diagram in the training slides show that the DRI is provided by OEMs.

Question: 

1.  What does the DRI image actually contain? Is it a copy of the valid firmware image that gets saved in flash after validation?
2. What is the difference between Normal and DRI mode? Is there any procedure to switch to normal from DRI mode?

Thanks in advance!