Loader (programming)
As loader (English loader ) is called the very basic service of an operating system , executable programs in the memory to load and run. Depending on the complexity of the operating system, this includes different tasks.
If this is the loader of the BIOS that the Bootloader starts the operating system, the task is limited only sure to download a boot block at a fixed address and continue execution at that address. The loaders of the simplest operating systems (for example the Atari XL-DOS) are not much more complex - the loader receives information about where the program is to be loaded from and into which memory area, loads the program and then jumps to the beginning of this memory area, see above that the program gets control.
The loader of a modern multitasking operating system that is currently starting a program ( creating a process ) has a lot more to do, namely reserving main memory for program and data segments in the operating system, loading the program into the designated main memory areas in a corresponding working memory model, the conversion of relative to absolute working memory addresses as well as the triggering of the binder , which dynamically integrates program libraries. However, control is not passed directly to the program afterwards; this is the task of the process scheduler in multitasking systems .
