8.5 Linker Command Files

Linker command files allow you to put linker options and directives in a file; this is useful when you invoke the linker often with the same options and directives. Linker command files are also useful because they allow you to use the MEMORY and SECTIONS directives to customize your application. You must use these directives in a command file; you cannot use them on the command line.

Linker command files are ASCII files that contain one or more of the following:

• Input filenames, which specify object files, archive libraries, or other command files. (If a command file calls another command file as input, this statement must be the last statement in the calling command file. The linker does not return from called command files.)
• Linker options, which can be used in the command file in the same manner that they are used on the command line
• The MEMORY and SECTIONS linker directives. The MEMORY directive defines the target memory configuration (see Section 8.5.4). The SECTIONS directive controls how sections are built and allocated (see Section 8.5.5.)
• Assignment statements, which define and assign values to global symbols

To invoke the linker with a command file, enter the cl430 --run_linker command and follow it with the name of the command file:

The linker processes input files in the order that it encounters them. If the linker recognizes a file as an object file, it links the file. Otherwise, it assumes that a file is a command file and begins reading and processing commands from it. Command filenames are case sensitive, regardless of the system used.

Example 1 shows a sample linker command file called link.cmd.