ARM Compiler toolchain Using the Linker - ARM Information Center

BPABI and SysV shared libraries and executables
10.4 About importing and exporting symbols for BPABI models
10.4.1 See also
In traditional linking, all symbols must be defined at link time for linking into a single
executable file containing all the required code and data. In platforms that support dynamic
linking, symbol binding can be delayed to load-time or in some cases, run-time. Therefore, the
application can be split into a number of modules, where a module is either an executable or a
shared library. Any symbols that are defined in modules other than the current module are
placed in the dynamic symbol table. Any functions that are suitable for dynamically linking to
at load or runtime are also listed in the dynamic symbol table.
There are two ways to control the contents of the dynamic symbol table:
• automatic rules that infer the contents from the ELF symbol visibility property
• manual directives that are present in a steering file.
These rules are slightly different for the SysV model.
Concepts
• Linker options for SysV models on page 10-13
• Automatic dynamic symbol table rules in the SysV memory model on page 10-15
• Addressing modes in the SysV memory model on page 10-17
• Thread local storage in the SysV memory model on page 10-18
• Related linker command-line options for the SysV memory model on page 10-19
• Linker options for bare metal and DLL-like models on page 10-21
• About symbol versioning on page 10-27.
Other information
• SysV ELF specification.
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