Static Loader

The static loader is a program that loads the entire executable program including, libraries and dependencies required by the program into the memory before the program gets executed.

• After loading the program into the memory, the loader resolves all the external dependencies in the program, this process is known as static linking.
• Once the linking is done, the loader updates the address of the program.
• No additional software is needed for loading and linking the entire program. 
• Static linking is applied for the static loader.
• Static loader is portable as it can work in any platform which supports the executable format used by the program.

Features of static Loader

• Pre-loading: Static loaders load all vital program modules into memory before execution starts.
• Compilation Time Linking: The method of linking and loading occurs at some point of the compilation segment of the program. This way that linking addresses and dependencies are resolved at assemble time.
• Predictable Execution Environment: Since all modules are loaded into memory before execution, the execution environment is predictable and deterministic.
• Faster Startup Times: Due to pre-loading, static loaders commonly have quicker startup instances in comparison to dynamic loaders due to the fact there’s no need to load modules at some stage in runtime.
• No Runtime Overhead: Once the loading is done, the program may be finished without delay without any extra overhead from the loader.

Advantages of Static Loader

• Static loaded is easy and simple to implement.
• As the entire program is loaded into the memory once, this makes the static loaded very much faster.
• Static loaded is reliable because it resolves all the external references before the execution of the program.

Disadvantages of Static Loader

• The main disadvantage of static loaded is wastage of memory because its load all the data and code into memory before execution. 
• Static loader is not flexible as it does not handles the dynamic loading of the data.
• Static loader is not efficient as the data or code that it loads, it may or may not be executed after.
• Static loader is inflexible because it does not adapt the changes in the program’s requirement at dynamic environment.

An Operating system is the critical component for managing the various memory resources in the computer system. One of the essential tasks of the operating system is to manage the executable programs or applications in the computer system. A program needs to be loaded into the memory for the purpose of execution. For the execution context, the loader comes into the picture.