Program Loading and Dynamic Linking

This chapter describes the object file information and system actions that create running programs. Most information here applies to all systems. Information specific to one processor resides in sections marked accordingly.

Executable and shared object files statically represent application programs. To execute such programs, the system uses the files to create dynamic program representations, or process images. A process image has segments that contain its text, data, stack, and so on. The following major sections are provided.

• Program Header describes object file structures that are directly involved in program execution. The primary data structure, a program header table, locates segment images in the file and contains other information that is needed to create the memory image of the program.

• Program Loading (Processor-Specific) describes the information used to load a program into memory.

• Runtime Linker describes the information used to specify and resolve symbolic references among the object files of the process image.