The relationship between a non-operating system and hardware, driver, and application software with an operating system

1. The relationship between hardware, driver and application software without operating system

In the absence of an operating system, the device-driven interface is delivered directly to the application software engineer, and the application does not span any level

The device-driven interface is accessed directly.

2. When there is an operating system, the relationship between hardware, driver, operating system and application software

When the system contains the operating system, we need to integrate the driver into the kernel, in order to achieve this fusion, must be in all device drivers

Design an interface to the operating system kernel, which is defined by the operating system and is consistent in structure for a class of devices, independent of the specific device.

Thus, when an operating system exists in the system, the drive becomes a bridge between the hardware and the kernel.

Why use the operating system?

1) a complex software system needs to handle multiple concurrent tasks, no operating system, and it is difficult to accomplish multi-task concurrency.

2) The operating system provides us with memory management mechanism, a typical example is, for most of the processors with MMU, Linux and other operating systems can let each

Processes can independently access 4GB of memory space.

3) When the driver is designed according to the device-independent interface given by the operating system, the application will be able to use a unified system call interface to access

Various equipment. For Linux, the application can access the character device and the block device through read, write. facilitates the development of application engineers.

The relationship between a non-operating system and hardware, driver, and application software with an operating system