2.7 Symbolic Relocations

The assembler treats each section as if it began at address 0. Of course, all sections cannot actually begin at address 0 in memory, so the linker must relocate sections. Relocations are symbol-relative rather than section-relative.

The linker can relocate sections by:

• Allocating them into the memory map so that they begin at the appropriate address as defined with the linker's MEMORY directive
• Adjusting symbol values to correspond to the new section addresses
• Adjusting references to relocated symbols to reflect the adjusted symbol values

The linker uses relocation entries to adjust references to symbol values. The assembler creates a relocation entry each time a relocatable symbol is referenced. The linker then uses these entries to patch the references after the symbols are relocated. Example 1 contains a code fragment for a TMS320C6000 device for which the assembler generates relocation entries.