Update export files

When you add an entry point to a BSO or CSO with an export file, the export file must be updated and the entry point added to either the local or global section as appropriate. The MakeTPF tools will automate some of this process by creating a copy of the existing export file in the working (build/) directory and inserting the new entry point into the global section of the new copy of the export file. You must edit the new export file and use it to replace the old export file in the source directory (exp/).