Reason why the program cannot be detached from the Operating System

The reason why the program cannot be separated from the operating system-Linux general technology-Linux programming and kernel information. The following is a detailed description. The operating system plays the following two roles:

1. Collect all system resources and allocate them to user processes as needed in order to coordinate the requests of many processes to system resources;

2. Provide functions required by any user process. For example, maintain a page table, such as disk IO. This is because of the first reason and simplified programming. Therefore, these programs cannot be executed without the operating system.

The Program for writing the "off" operating system is mainly to complete the initialization of CPU and peripherals. After the initialization is complete, try to read the program from the ROM to the main memory and initialize the CPU register, point the command counter (a combination of CS: IP on i386) to the beginning of the program code to start running. For convenience, the i386 series CPU can work in the real mode, saving the trouble of working in the protection mode.

The system initialization and register initialization are system-related throughout the process. Refer to the initialization code of lilo and Linux kernel.

All of the above are the cases where the system runs only one process at a time. If multiple processes run concurrently, you need to write a piece of scheduling and coordination code, which is an operating system.