DBL links the modules of a load unit in the following steps:
Primary input
DBL searches for the module specified in the load call.Resolution of external references
DBL tries to find matching names of control sections (CSECTs) and entry points (ENTRYs) for all external references in this module. For this, DBL searches for the appropriate modules in the secondary input and links these into the load unit. If the modules added in this manner result in further unresolved external references, this step is repeated iteratively until all external references have been resolved or until a previously declared status for unresolved external references is achieved.COMMON section processing
DBL checks all modules for COMMON section definitions and reserves memory space for these.Address relocation
All addresses contained in the modules are converted so that they refer to the same reference address.
These steps in the linkage process are described in detail below. Special features regarding the loading of list name units and PAM-LLMs are described in "Management of list name units" and in "Loading LLMs from files (PAM-LLMs)".