Core boot files' location is not readily available. There is no single consistent file with such purpose as is for tce (.tce_dir). Instead such location is in the boot loader. As we don't enforce any particular boot loader, it would mean trying to scan and parse a myriad of boot loaders, and then possibly, even likely, find several candidates. Even if a scan of the entire drives is attempted the boot files are not required to be at root-level as is tce and where scanning is an available option. Various boot loaders allow boot files to be placed nearly anywhere so therefore a total scan could be very time consuming with still a possibilty of find multiples or could possible be on a removable device that is not even available to attempt mounting. Is such effort worth it when typically a base upgrade is copying over one file?