How SOF Uses Checkpoint Files

SOF uses checkpoint files to store information about the about the environment. There are 3 distinct types of info:

Hardware configuration for the local system
The information for CHPIDs, devices, control units, and switches is identified during the discovery process. Saving this information in the checkpoint file provides a significant reduction of initialization elapsed time when SOF restarts. If SOF determines that the configuration has not changed, it will use the checkpoint information, bypassing the need to probe each device path for the DEVID info.
Switch names dynamically added using the WRITENAME command
Without the checkpoint file, the names would be lost at shutdown.
Status for each known external system
After a restart, SOF restores the status of each system. Any systems that have been previously RESET are marked as DOWN; all others are marked as Inactive or Pending. Without the checkpoint file information, the DOWN systems would need operator intervention; more importantly, SOF would not know about external systems until there is CCI activity from them.

Use of checkpoint file is optional, but highly recommended. Normally, a single file for each system is sufficient.