Linker

The compiler organizes its object code into sections that the linker arranges when it creates its output file.

To generate an output file, the linker reads from input ELF (Executable and Linkable Format) files generated by compiler and other tools. The linker also reads a linker command file to determine how to build its output file. The linker then writes to its output file, an ELF file. This output file is the executable image, ready to load and run on the target platform.

This chapter explains the sections in the object code of and how to arrange them in the linker's output file:

• Specifying Link Order in the IDE
  To specify link order, use the Link Order page of the CodeWarrior IDE's Project window.
• Dead-Stripping
  Dead-stripping ensures the smallest possible output file. Also, dead-stripping relieves you from having to manually exclude unused source code from the compiler and unused object code from the linker.
• Defining the Target's Memory Map
  Use the linker command file's MEMORY directive to delineate areas in the target platform's memory map and associate a name for each of these areas.
• Defining Sections in the Output File
  Use the linker command file's SECTIONS directive to define sections in the linker's output file.
• Associating Input Sections With Output Sections
  The linker command file's SECTIONS and GROUP directives allow you to specify other ways to associate input object code with sections in linker output.
• Controlling Alignment
  Use the ALIGN argument in a SECTIONS or GROUP directive to specify an alignment relative to the start of the physical address.
• Specifying Memory Area Locations and Sizes
  Use the BIND , ADDR , and SIZEOF keywords in SECTIONS and GROUP directives to precisely specify where sections in the output file will be loaded.
• Creating Memory Gaps
  Create gaps in memory by performing alignment calculations.
• Creating Symbols
  Create symbols that you can use in your program by assigning a symbol to some value in your linker command file.
• Linker Command File Syntax
  Linker command file syntax is a notation and implies what an LCF file includes.
• Commands, Directives, and Keywords
  Explanations of all valid LCF functions, keywords, directives, and commands.