Operating System Concepts - Computer System Structure Quiz

Study Notes

A computer system can be divided into four components: hardware, operating system, application programs, and users.
Hardware provides basic computing resources such as CPU, memory, and I/O devices.
Operating system controls and coordinates the use of hardware among various applications and users.
Application programs define how system resources are used to solve computing problems for users.
Users can be people, machines, or other computers.

A bootstrap program is loaded at power-up or reboot.
It is typically stored in ROM or EPROM, known as firmware.
The bootstrap program initializes all aspects of the system and loads the operating system kernel.

Firmware is a specific type of software that acts as an intermediary between software and hardware.

One or more CPUs and device controllers connect through a common bus providing access to shared memory.
The CPU and devices compete for memory cycles.
I/O devices and the CPU can execute concurrently.
Each device controller is in charge of a particular device type and has a local buffer.
The CPU moves data from/to main memory to/from local buffers.
I/O is from the device to the local buffer of the controller.
The device controller informs the CPU that it has finished its operation by causing an interrupt.

Interrupts transfer control to the interrupt service routine through the interrupt vector.
The interrupt architecture must save the address of the interrupted instruction.
A trap or exception is a software-generated interrupt caused by an error or user request.

An operating system is a resource allocator that manages all resources and decides between conflicting requests for efficient and fair resource use.
An operating system is a control program that controls the execution of programs to prevent errors and improper use of the computer.