What is the function of a linker script?

A linker script controls the linking process, defining how sections in the input files are mapped into the output file.

A linker script is a crucial component in the process of creating an executable program from object files. It is used by the linker, a program that takes one or more object files generated by a compiler and combines them into a single executable file. The linker script provides instructions to the linker on how to perform this task.

The primary function of a linker script is to control the memory layout of the output file. It defines where in memory each section of the input files will be placed in the output file. This is particularly important in embedded systems, where memory is often limited and specific memory locations may have special purposes.

In addition to controlling the memory layout, a linker script can also define symbols. Symbols are essentially names for memory locations. By defining symbols in the linker script, you can refer to specific memory locations in your code by name, rather than by their actual memory address. This can make your code easier to read and understand.

Linker scripts can also control the order in which sections from the input files are placed in the output file. This can be important for performance reasons, as the order in which sections are placed in memory can affect how quickly the program runs.

In summary, a linker script is a powerful tool that gives you control over the linking process. It allows you to define the memory layout of your program, name specific memory locations, and control the order of sections in the output file. Understanding how to use a linker script can give you a deeper understanding of how your program is constructed and how it runs.