Contents of the 16 byte Sercomm trailer at the end of the flash. It is used by Redboot to detect a Sercomm flash layout and to configure the Sercomm upgrade system.
The magic number is necessary to use the boot command which is called by the default boot script. If you are not using the upgrade system then the other trailer fields do not need to be filled out.
If the default boot script is changed to "move; exec 0x01d00000" then the trailer does not need to be present.