BL51 User's Guide

Resolving External References

When you compile or assemble a source file, external references are created for variables and functions that are accessed but declared in different source files. In addition, public symbols are created in the object module for the variables and functions declared in that source file.

The linker uses public symbols to resolve the addresses of external references. For each external reference, a public symbol with the same name and attributes must exist.

The linker builds a table of all public and external symbols it encounters. External references are resolved with public references (as long as the names match and the symbol attributes correspond). The linker reports an error if the symbol types of an external and public symbol do not match. The linker also reports an error if no public symbol is found for an external reference.

The absolute addresses of the public symbols are resolved after the location of the segments is determined.